OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
a(3) = 6 because A000005(6!) = 30 is divisible by 3.
MATHEMATICA
Table[k = 1; While[! Divisible[DivisorSigma[0, k!], n], k++]; k, {n, 120}] (* Michael De Vlieger, Aug 07 2016 *)
With[{c=Table[{k, DivisorSigma[0, k!]}, {k, 250}]}, Table[SelectFirst[ c, Divisible[ #[[2]], n]&], {n, 70}]][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 17 2019 *)
PROG
(PARI) a(n) = {my(k = 1); while(numdiv(k!) % n != 0, k++); k; }
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Jul 29 2016
STATUS
approved