|
| |
|
|
A066459
|
|
Product of factorials of the digits of n.
|
|
5
| |
|
|
1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 2, 2, 4, 12, 48, 240, 1440, 10080, 80640, 725760, 6, 6, 12, 36, 144, 720, 4320, 30240, 241920, 2177280, 24, 24, 48, 144, 576, 2880, 17280, 120960, 967680
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
LINKS
| Harry J. Smith, Table of n, a(n) for n=0,...,1000
Eric Weisstein's World of Mathematics, Factorial</a
Index entries for sequences related to factorial numbers
|
|
|
FORMULA
| If n=10*q+r,(0<=r<10) then a(n)=(q+1+r)!*(sum((-1)^(q-k)*binomial(r,k)/(q+1+r-k),k=0..r)); [From Milan R. Janjic (agnus(AT)blic.net), Dec 14 2008]
|
|
|
EXAMPLE
| a(24) = (2!) * (4!) = 2 * 24 = 48.
|
|
|
PROG
| (PARI) { for (n=0, 1000, m=n; a=1; while (m>0, d=m%10; m=(m-d)/10; a*=d!); write("b066459.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Feb 15 2010]
(Haskell)
import Data.List (unfoldr)
a066459 = product . map a000142 .
unfoldr (\x -> if x == 0 then Nothing else Just $ swap $ divMod x 10)
-- Reinhard Zumkeller, Oct 11 2011
|
|
|
CROSSREFS
| Cf. A000142, A034879 (iterated).
Sequence in context: A054873 A193936 A072132 * A071937 A061602 A033647
Adjacent sequences: A066456 A066457 A066458 * A066460 A066461 A066462
|
|
|
KEYWORD
| base,easy,nonn
|
|
|
AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), Jan 02 2002
|
| |
|
|
