A119847 Positions where A119842 is zero.

6, 10, 14, 15, 21, 22, 24, 26, 30, 33, 34, 35, 38, 39, 40, 42, 46, 51, 54, 55, 56, 57, 58, 60, 62, 65, 66, 69, 70, 74, 77, 78, 82, 84, 85, 86, 87, 88, 90, 91, 93, 94, 95, 96, 102, 104, 105, 106, 110, 111, 114, 115, 118, 119, 122, 123, 126, 129, 130, 132, 133, 134

Offset: 1

Author

Antti Karttunen, Jun 04 2006

Keywords

• nonn

Comments

In addition to the terms of A119899 includes also terms with prime signature p*q*r, e.g. 30 (= 2*3*5). Anything else?

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..6677

Crossrefs

Complement: A119848. Superset of A119899. Cf. A119850.

Cf. A229153.

Programs

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}]]; c[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]]]; A119847 = Position[ Table[c[n], {n, 1, 200}], 0] // Flatten (* Jean-François Alcover, Mar 03 2016, after Alois P. Heinz *)