OFFSET
1,2
LINKS
Michel Lagneau, Table of n, a(n) for n = 1..10000
EXAMPLE
MATHEMATICA
lst={}; f[n_]:=DivisorSigma[1, n]/Plus@@Select[Divisors@n, #<=Sqrt@n&]; Do[If[IntegerQ[f[n]], AppendTo[lst, f[n]]], {n, 1, 200}]; lst
PROG
(PARI) lista(nn) = { for(n = 1, nn, q = sigma(n) / sumdiv(n, d, d*(d<=sqrt(n))); if (type(q) == "t_INT", print1(q, ", ")); ); } \\ Michel Marcus, Mar 05 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Feb 27 2014
STATUS
approved