login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A190997
Product of digits of all the divisors of n.
4
1, 2, 3, 8, 5, 36, 7, 64, 27, 0, 1, 288, 3, 56, 75, 384, 7, 2592, 9, 0, 42, 8, 6, 18432, 50, 72, 378, 3584, 18, 0, 3, 2304, 27, 168, 525, 373248, 21, 432, 243, 0, 4, 16128, 12, 512, 13500, 288, 28, 3538944, 252, 0, 105, 2880, 15, 725760, 125, 860160, 945
OFFSET
1,2
COMMENTS
Product of digits of concatenation of all divisors of n (A037278).
LINKS
FORMULA
a(n) = 0 for n = multiples of 10; a(A008592(n)) = 0 for n >=1.
EXAMPLE
For n = 12: a(12) = 1 * 2 * 3 * 4 * 6 * 1 * 2 = 288.
MAPLE
A190997:=proc(n) local d, i, p: d:=numtheory[divisors](n): p:=1: for i from 1 to nops(d) do p:=p*mul(d, d=convert(d[i], base, 10)): od: return p: end: seq(A190997(n), n=1..57); # Nathaniel Johnston, Jun 15 2011
MATHEMATICA
Table[Times@@Flatten[IntegerDigits/@Divisors[n]], {n, 100}] (* Harvey P. Dale, Nov 27 2022 *)
PROG
(PARI) a007954(n) = my(d=digits(n)); prod(i=1, #d, d[i]);
a(n) = my(div=divisors(n), pdt=1); for(k=1, #div, pdt=pdt*a007954(div[k])); pdt \\ Felix Fröhlich, Sep 22 2016
CROSSREFS
Sequence in context: A376016 A091136 A140651 * A184392 A007955 A324502
KEYWORD
nonn,easy,base
AUTHOR
Jaroslav Krizek, Jun 15 2011
STATUS
approved