1,2

Table of n, a(n) for n=1..70.

a(3) = 6 because A000005(6!) = 30 is divisible by 3.

Table[k = 1; While[! Divisible[DivisorSigma[0, k!], n], k++]; k, {n, 120}] (* Michael De Vlieger, Aug 07 2016 *)

(PARI) a(n) = {my(k = 1); while(numdiv(k!) % n != 0, k++); k; }

Cf. A000005, A027423.

Sequence in context: A177209 A274439 A280342 * A185380 A136695 A154129

Adjacent sequences: A275473 A275474 A275475 * A275477 A275478 A275479

nonn

Altug Alkan, Jul 29 2016

approved