1,2

Chai Wah Wu, Table of n, a(n) for n = 1..10000

a(5) = 4 because sigma(4!) = 60 is divisible by 5.

Table[k = 1; While[! Divisible[DivisorSigma[1, k!], n], k++]; k, {n, 84}] (* Michael De Vlieger, Aug 08 2016 *)

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

Cf. A000203, A062569.

Sequence in context: A147658 A221529 A105161 * A094365 A272886 A098822

Adjacent sequences: A275766 A275767 A275768 * A275770 A275771 A275772

nonn

Altug Alkan, Aug 08 2016

approved