A330650 Terms of A330606 which are not squares or powers of 2.

1250, 4802, 31250, 57122, 167042, 235298, 260642, 320000, 559682, 941192, 1229312, 1414562, 3001250, 3543122, 3748322, 5120000, 6837602, 8000000, 9653618, 9759362, 14172488, 14623232, 15059072, 15780962, 19531250, 19668992, 24234722, 35701250, 38614472, 40302242

Offset

1,1

Links

Giovanni Resta, Table of n, a(n) for n = 1..655 (terms < 10^13; first 155 terms from Amiram Eldar and Robert G. Wilson v)

Mathematica

fQ[n_] := CoprimeQ[n*DivisorSigma[0, n], DivisorSigma[1, n]] && !IntegerQ@ Sqrt@ n && !IntegerQ@ Log2@ n; Select[Range[10^6], fQ@# &]

Prog

(Magma) [k:k in [1..10000000]|Gcd(k*NumberOfDivisors(k), DivisorSigma(1, k)) eq 1 and (not IsSquare(k)) and (not IsIntegral(Log(2, k)))]; // Marius A. Burtea, Dec 23 2019

Crossrefs

Cf. A330606.

Sequence in context: A120376 A231805 A122272 * A195810 A184610 A106322

Adjacent sequences: A330647 A330648 A330649 * A330651 A330652 A330653

Keyword

nonn

Author

Amiram Eldar and Robert G. Wilson v, Dec 22 2019

Status

approved