

A061603


a(n) = n! / {product of factorials of the digits of n}.


2



1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3628800, 39916800, 239500800, 1037836800, 3632428800, 10897286400, 29059430400, 70572902400, 158789030400, 335221286400, 1216451004088320000, 25545471085854720000, 281000181944401920000
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OFFSET

0,11


COMMENTS

It can be shown that the terms obtained by the above formula are positive integers using the fact that k! divides a product of k consecutive numbers.


LINKS



FORMULA



EXAMPLE

a(12) = (12!) / { (1!)(2!) = 239500800.


MATHEMATICA

Table[n!/Times@@(IntegerDigits[n]!), {n, 0, 30}] (* Harvey P. Dale, Jan 19 2017 *)


PROG

(PARI) { for (n=0, 100, p=1; x=n; until (x==0, p*=(x  10*(x\10))!; x\=10); write("b061603.txt", n, " ", n!/p) ) } \\ Harry J. Smith, Jul 25 2009
(PARI) a(n) = my(d = digits(n)); n!/prod(k=1, #d, d[k]!); \\ Michel Marcus, Jul 02 2018


CROSSREFS



KEYWORD

nonn,base,easy


AUTHOR



EXTENSIONS



STATUS

approved



