OFFSET
1,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1281
MATHEMATICA
b[s_, t_] := b[s, t] = If[Length[s] < 1, 1, Sum[If[Mod[PrimeOmega[x], 2] == 1 - t && Length[Select[s, Mod[#, x] == 0 &]] == 1, b[s~Complement~{x}, 1 - t], 0], {x, s}]]; a[n_] := Module[{l, m}, l = Sort[FactorInteger[n], #1[[2]] > #2[[2]] &]; m = Product[Prime[i]^l[[i]][[2]], {i, 1, Length[l]} ]; b[Divisors[m][[2 ;; -2]], Mod[PrimeOmega[m], 2]]]; A119842 = Array[a, 1000]; A119850 = Position[A119842, n_ /; n > 1] // Flatten (* Jean-François Alcover, Mar 03 2016, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 04 2006
STATUS
approved