A156943 Odd abundant numbers not divisible by 25 whose abundancy is odd.

81162081, 138791961, 173369889, 441882441, 730458729, 1091179089, 1249127649, 1524043521, 1560329001, 1744649361, 2286465489, 2606204601, 3255501249, 3976941969, 4770526761, 5567099769, 6574128561, 6800806089, 7584145569

Offset

1,1

Comments

Number of terms < 10^n: 0, 0, 0, 0, 0, 0, 0, 1, 5, 25, 63, ..., .

Links

Robert G. Wilson v, Table of n, a(n) for n=1..1005

Mathematica

q[n_] := Module[{ab = DivisorSigma[1, n] - 2*n}, ab > 0 && OddQ[ab]]; Select[Range[1, 7775536039, 2], ! Divisible[#, 25] && q[#] &] (* corrected by Amiram Eldar, Oct 10 2023 *)

Crossrefs

Subsequence of A156903 and A156942.

Sequence in context: A210164 A119075 A136965 * A120316 A118079 A186091

Adjacent sequences: A156940 A156941 A156942 * A156944 A156945 A156946

Keyword

nonn

Author

Robert G. Wilson v, Feb 18 2009

Extensions

Name corrected by Amiram Eldar, Oct 10 2023

Status

approved