Actuarial Outpost
 
Go Back   Actuarial Outpost > Cyberchat > Non-Actuarial Topics
FlashChat Actuarial Discussion Preliminary Exams CAS/SOA Exams Cyberchat Around the World Suggestions

Search Actuarial Jobs by State @ DWSimpson.com:
AL AK AR AZ CA CO CT DE FL GA HI ID IL IN IA KS KY LA
ME MD MA MI MN MS MO MT NE NH NJ NM NY NV NC ND
OH OK OR PA RI SC SD TN TX UT VT VA WA WV WI WY

Reply
 
Thread Tools Search this Thread Display Modes
  #41  
Old 02-07-2020, 02:25 PM
BlackPhillip BlackPhillip is offline
Member
Non-Actuary
 
Join Date: Jan 2019
Posts: 1,537
Default

Quote:
Originally Posted by Sloop John B View Post
AO isn't letting me upvote this comment
Reply With Quote
  #42  
Old 02-24-2020, 10:23 AM
Super Silver Haze Super Silver Haze is offline
aadeeikklllMMPrSuzzz
CAS
 
Join Date: Mar 2004
Posts: 22,329
Blog Entries: 6
Default

I don't think I'd ever heard of a "double factorial" before today.

Quote:
In mathematics, the double factorial or semifactorial of a number n is the product of all the integers from 1 up to n that have the same parity as n. For example, 9!! = 9 7 5 3 1 = 945.
__________________
2018 RPS BIGGEST LOSER
Spoiler:
Aaaaaaaah!/Academy Of Muses/Age of Shadows/Among The Living/Brigsby Bear/Chained For Life/The Challenge/The Field Guide to Evil/Hacksaw Ridge/Housewife/The Innocents/It/Journeyman/Mohawk/My Happy Family/Nostalgia/The Party/Paul Verhoeven's Tricked/Profile/Puzzle/Share/Silence/State Like Sleep
Reply With Quote
  #43  
Old 02-24-2020, 10:38 AM
Funemployed Funemployed is offline
Member
CAS Non-Actuary
 
Join Date: Feb 2011
Location: Above it all
College: Ball State Alumni
Favorite beer: Root or Birch
Posts: 2,778
Default

"parity", as in odd/even? Never heard that term before.

I'd heard of semi-factorial, but haven't heard of double factorial refering to the same thing. (Must be the same thing as people using semi-annual and bi-annual to mean twice a year)
Reply With Quote
  #44  
Old 02-24-2020, 11:15 AM
JollyGoodFCAS's Avatar
JollyGoodFCAS JollyGoodFCAS is offline
Member
CAS AAA
 
Join Date: Dec 2006
Location: Earth (most of the time)
Favorite beer: Beer-Sheva
Posts: 38,443
Default

Quote:
Originally Posted by Super Silver Haze View Post
I don't think I'd ever heard of a "double factorial" before today.
That is interesting - I always thought that it was just the factorial of the factorial (e.g., 3!!=720). Having used an 8-digit calculator back in high school, I enjoyed how high I could get a factorial before I got an error. For single factorials it was 69!, and for what I thought was a double factorial it was 4!!. That's why I always liked the number 2!!!!!!!!!
__________________
Quote:
Originally Posted by lit041000 View Post
FCAS is the yoda of puns. He sprinkles little treasures when the pun gods smile upon us
Reply With Quote
  #45  
Old 02-25-2020, 08:59 AM
Marcie's Avatar
Marcie Marcie is offline
Member
CAS
 
Join Date: Feb 2015
Posts: 10,027
Default

Quote:
Originally Posted by Funemployed View Post
"parity", as in odd/even?
Don't forget Tromey integers too!
Reply With Quote
  #46  
Old 02-25-2020, 09:33 AM
1695814's Avatar
1695814 1695814 is online now
Member
SOA AAA
 
Join Date: Aug 2002
Studying for nothing. I quit.
Favorite beer: Root
Posts: 38,565
Default

Quote:
Originally Posted by JollyGoodFCAS View Post
That is interesting - I always thought that it was just the factorial of the factorial (e.g., 3!!=720). Having used an 8-digit calculator back in high school, I enjoyed how high I could get a factorial before I got an error. For single factorials it was 69!, and for what I thought was a double factorial it was 4!!. That's why I always liked the number 2!!!!!!!!!
Would one need to use parenthesis to denote the factorial of a factorial then?

(3!)!=720

Has the factorial of a factorial ever been used in legitimate mathematics?

p.s. Here's a nice little article from Wolfram MathWorld on the double factorial -- http://mathworld.wolfram.com/DoubleFactorial.html
__________________
Help find a cure for COVID-19. Click here.


The CDC recommends watching the Rock Paper Scissors tournament from a distance of at least six posts.


Sheep Dog Dare Game Champion

Last edited by 1695814; 02-25-2020 at 09:39 AM..
Reply With Quote
  #47  
Old 02-25-2020, 10:52 AM
JollyGoodFCAS's Avatar
JollyGoodFCAS JollyGoodFCAS is offline
Member
CAS AAA
 
Join Date: Dec 2006
Location: Earth (most of the time)
Favorite beer: Beer-Sheva
Posts: 38,443
Default

Quote:
Originally Posted by 1695814 View Post
Would one need to use parenthesis to denote the factorial of a factorial then?

(3!)!=720
(Who cares?)!
__________________
Quote:
Originally Posted by lit041000 View Post
FCAS is the yoda of puns. He sprinkles little treasures when the pun gods smile upon us
Reply With Quote
  #48  
Old 02-25-2020, 10:56 AM
1695814's Avatar
1695814 1695814 is online now
Member
SOA AAA
 
Join Date: Aug 2002
Studying for nothing. I quit.
Favorite beer: Root
Posts: 38,565
Default

Quote:
Originally Posted by JollyGoodFCAS View Post
(Who cares?)!
(I do!)!
__________________
Help find a cure for COVID-19. Click here.


The CDC recommends watching the Rock Paper Scissors tournament from a distance of at least six posts.


Sheep Dog Dare Game Champion
Reply With Quote
  #49  
Old 02-25-2020, 02:32 PM
Funemployed Funemployed is offline
Member
CAS Non-Actuary
 
Join Date: Feb 2011
Location: Above it all
College: Ball State Alumni
Favorite beer: Root or Birch
Posts: 2,778
Default

Quote:
Originally Posted by Marcie View Post
Don't forget Tromey integers too!
Now you're just Troming
Reply With Quote
  #50  
Old 02-26-2020, 07:30 AM
Chief Petosky's Avatar
Chief Petosky Chief Petosky is offline
Member
 
Join Date: Oct 2005
Location: Location: Location
Favorite beer: BBC Bourbon Stout
Posts: 20,778
Default

Quote:
It's well known that the album The Wall loops on itself with "Isn't this where..." in the last seconds of the last song, and "...we came in?"
I did not know about the "Isn't this where...we came" in loop until a couple weeks ago (so, yes, not today). Got The Wall CD for Christmas and have been listening to it a lot on my iPod. It had been years since I listened to the whole album (probably on vinyl). Was looking some things up on it and learned something new!
__________________
You move me, you move me, With your buildings and your eyes; autumn woods and winter skies
You move me, you move me. Open sea and city lights, busy streets and dizzy heights
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -4. The time now is 02:35 PM.


Powered by vBulletin®
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
*PLEASE NOTE: Posts are not checked for accuracy, and do not
represent the views of the Actuarial Outpost or its sponsors.
Page generated in 0.21009 seconds with 11 queries