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A119845 Positions where new distinct values appear in A119842. 3
1, 6, 36, 72, 120, 144, 180, 192, 288, 420, 432, 480, 576, 720, 900, 1080, 1152, 1296, 1680, 1728, 1800, 1920, 2304, 2520, 2592, 2880, 3072, 3600, 4320, 4608, 5184, 6300, 6480, 6720, 6912, 7200, 7680, 9216, 9240 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(16) is greater than 960.

LINKS

Table of n, a(n) for n=1..39.

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_] := 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]]]; Join[{1}, Reap[For[ k = 2, k < 10^4, k++, If[FreeQ[Array[a, k - 1], a[k]], Print[k, " ", a[k]]; Sow[k]]]][[2, 1]]] (* Jean-Fran├žois Alcover, Mar 03 2016, after Alois P. Heinz *)

CROSSREFS

Subset of A025487. Cf. A119846, A119843.

Sequence in context: A139249 A070150 A161144 * A208064 A207929 A171506

Adjacent sequences:  A119842 A119843 A119844 * A119846 A119847 A119848

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jun 04 2006

EXTENSIONS

a(16)-a(39) from Alois P. Heinz, Feb 26 2016

STATUS

approved

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Last modified October 17 14:47 EDT 2019. Contains 328114 sequences. (Running on oeis4.)