A306983 - OEIS

A306983

Infinitary pseudoperfect numbers: numbers n equal to the sum of a subset of their proper infinitary divisors.

6, 24, 30, 40, 42, 54, 56, 60, 66, 72, 78, 88, 90, 96, 102, 104, 114, 120, 138, 150, 168, 174, 186, 210, 216, 222, 246, 258, 264, 270, 280, 282, 294, 312, 318, 330, 354, 360, 366, 378, 384, 390, 402, 408, 420, 426, 438, 440, 456, 462, 474, 480, 486, 498, 504

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OFFSET

1,1

COMMENTS

Subsequence of A005835.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

idivs[x_] := If[x == 1, 1, Sort@Flatten@Outer[Times, Sequence @@ (FactorInteger[x] /. {p_, m_Integer} :> p^Select[Range[0, m], BitOr[m, #] == m &])]]; s = {}; Do[d = Most[idivs[n]]; c = SeriesCoefficient[Series[Product[1 + x^d[[i]], {i, Length[d]}], {x, 0, n}], n]; If[c > 0, AppendTo[s, n]], {n, 2, 1000}]; s

CROSSREFS

Cf. A005835, A007357, A049417, A126168, A129656, A293188, A292985, A318100, A306984.

Sequence in context: A292985 A335197 A364053 * A234648 A110926 A131906

Adjacent sequences: A306980 A306981 A306982 * A306984 A306985 A306986

KEYWORD

nonn

AUTHOR

Amiram Eldar, Mar 18 2019

STATUS

approved