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A119847 Positions where A119842 is zero. 5
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

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-Fran├žois Alcover, Mar 03 2016, after Alois P. Heinz *)

CROSSREFS

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

Cf. A229153.

Sequence in context: A268376 A067582 A229153 * A279458 A119899 A130092

Adjacent sequences:  A119844 A119845 A119846 * A119848 A119849 A119850

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jun 04 2006

STATUS

approved

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Last modified January 19 17:45 EST 2019. Contains 319309 sequences. (Running on oeis4.)