A329188 Odd unitary admirable numbers: the odd terms of A328328.

80535, 354585, 403095, 430815, 437745, 442365, 5388495, 6126645, 9338595, 36340395, 130689195, 747242265, 1335049485, 2224695165, 4085490255, 9665740455, 10394173335, 11534750535, 13837748925, 33378237165, 73088757105, 94849396005, 109544822205, 216654032595

Offset: 1

Author

Amiram Eldar, Nov 07 2019

Keywords

• nonn

Comments

Of the first 10^4 unitary admirable numbers only 6 are odd.

a(21) > 6*10^10.

Links

• Giovanni Resta, Table of n, a(n) for n = 1..43 (terms < 10^13)

Crossrefs

The unitary version of A109729.

Intersection of A005408 and A328328.

Subsequence of A129485.

Programs

Mathematica

usigma[1] = 1; usigma[n_] := Times @@ (1 + Power @@@ FactorInteger[n]); uadmQ[n_] := (ab = usigma[n] - 2 n) > 0 && EvenQ[ab] && ab/2 < n && Divisible[n, ab/2] && CoprimeQ[2*n/ab, ab/2]; s = {}; Do[If[uadmQ[n], AppendTo[s, n]], {n, 1, 10^6, 2}]; s

Extensions

Data corrected by Amiram Eldar, May 12 2020

Terms a(21) and beyond from Giovanni Resta, May 12 2020