A348275 Odd noninfinitary abundant numbers: the odd terms of A348274.

99225, 1091475, 1289925, 1334025, 1576575, 1686825, 1715175, 1863225, 1885275, 2027025, 2061675, 2282175, 2304225, 2395575, 2401245, 2436525, 2480625, 2650725, 2723175, 2789325, 2877525, 2962575, 3031875, 3075975, 3132675, 3185325, 3186225, 3296475, 3353805, 3501225

Offset

1,1

Comments

The number of terms below 10^k, for k = 5, 6, ..., are 1, 113, 630, 7771, 73685, ... Apparently this sequence has an asymptotic density 0.000007...

Links

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

Example

99225 is a term since A348271(99225) = 107207 > 99225.

Mathematica

f[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 @@ f @@@ FactorInteger[n]; s[n_] := DivisorSigma[1, n] - isigma[n]; Select[Range[1, 2*10^6, 2], s[#] > # &]

Crossrefs

Cf. A348271.

Subsequence of A005231 and A348274.

Similar sequences: A094889, A127666, A129485, A293186, A321147.

Sequence in context: A255753 A254842 A339936 * A138732 A108224 A268417

Adjacent sequences: A348272 A348273 A348274 * A348276 A348277 A348278

Keyword

nonn

Author

Amiram Eldar, Oct 09 2021

Status

approved