login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A066459 Product of factorials of the digits of n. 7

%I

%S 1,1,2,6,24,120,720,5040,40320,362880,1,1,2,6,24,120,720,5040,40320,

%T 362880,2,2,4,12,48,240,1440,10080,80640,725760,6,6,12,36,144,720,

%U 4320,30240,241920,2177280,24,24,48,144,576,2880,17280,120960,967680

%N Product of factorials of the digits of n.

%H Harry J. Smith and Indranil Ghosh, <a href="/A066459/b066459.txt">Table of n, a(n) for n = 0..10000</a> (first 1001 terms from Harry J. Smith)

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Factorial.html">Factorial</a>

%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>

%F 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)); _Milan Janjic_, Dec 14 2008]

%e a(24) = (2!) * (4!) = 2 * 24 = 48.

%p A066459 := proc(n)

%p local a,d;

%p a := 1 ;

%p for d in convert(n,base,10) do

%p a := a*d! ;

%p end do:

%p a ;

%p end proc: # _R. J. Mathar_, Aug 07 2014

%o (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) ) } \\ _Harry J. Smith_, Feb 15 2010

%o (Haskell)

%o import Data.List (unfoldr)

%o a066459 = product . map a000142 .

%o unfoldr (\x -> if x == 0 then Nothing else Just $ swap $ divMod x 10)

%o -- _Reinhard Zumkeller_, Oct 11 2011

%o (Python)

%o import math

%o def A066459(n):

%o s=1

%o for i in str(n):

%o s*=math.factorial(int(i))

%o return s # _Indranil Ghosh_, Jan 11 2017

%Y Cf. A000142, A034879 (iterated).

%K base,easy,nonn

%O 0,3

%A _Jason Earls_, Jan 02 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 21 15:02 EDT 2019. Contains 323443 sequences. (Running on oeis4.)