A334975 Odd infinitary admirable numbers: the odd terms of A334974.

945, 43065, 46035, 80535, 354585, 403095, 430815, 437745, 442365, 2305875, 3525795, 4404105, 4891887, 5388495, 5927985, 6126645, 6220665, 6375105, 6537375, 7853625, 8109585, 8731125, 9071865, 9338595, 9784125, 13241745, 23760555, 33381855, 34592805, 35642295

Offset

1,1

Comments

Of the first 10^4 infinitary admirable numbers only 9 are odd.

Links

Table of n, a(n) for n=1..30.

Mathematica

fun[p_, e_] := Module[{b = IntegerDigits[e, 2], m}, m = Length[b]; Product[If[b[[j]] > 0, 1 + p^(2^(m - j)), 1], {j, 1, m}]]; isigma[1] = 1; isigma[n_] := Times @@ fun @@@ FactorInteger[n]; infDivQ[n_, 1] = True; infDivQ[n_, d_] := BitAnd[IntegerExponent[n, First /@ (f = FactorInteger[d])], (e = Last /@ f)] == e; infAdmQ[n_] := (ab = isigma[n] - 2 n) > 0 && EvenQ[ab] && ab/2 < n && Divisible[n, ab/2] && infDivQ[n, ab/2]; Select[Range[1, 5*10^5, 2], infAdmQ]

Crossrefs

The infinitary version of A109729.

Intersection of A005408 and A334974.

Subsequence of A127666.

Cf. A329188, A334973.

Sequence in context: A335055 A133818 A334973 * A289953 A112491 A263889

Adjacent sequences: A334972 A334973 A334974 * A334976 A334977 A334978

Keyword

nonn

Author

Amiram Eldar, May 18 2020

Status

approved