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

1,1

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)

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

Crossrefs

The unitary version of A109729.

Intersection of A005408 and A328328.

Subsequence of A129485.

Sequence in context: A102457 A102459 A347906 * A095946 A264805 A050517

Adjacent sequences: A329185 A329186 A329187 * A329189 A329190 A329191

Keyword

nonn

Author

Amiram Eldar, Nov 07 2019

Extensions

Data corrected by Amiram Eldar, May 12 2020

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

Status

approved