A076375 Numbers k such that both k and 2*k are balanced numbers (A020492).

1, 3, 6, 15, 35, 70, 105, 210, 357, 420, 1045, 1485, 2090, 2970, 3135, 3339, 5049, 5940, 6270, 10659, 12441, 12540, 16065, 24871, 24969, 29029, 33915, 35343, 39105, 39585, 49742, 50065, 58058, 58435, 64285, 70686, 71145, 74613, 78210, 87087

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (calculated using data from Jud McCranie, terms 1..1000 from Donovan Johnson)

Mathematica

f[x_] := DivisorSigma[1, x]/EulerPhi[x] Do[s=f[n]; s1=f[2*n]; If[IntegerQ[s]&&IntegerQ[s1], Print[n]], {n, 1, 100000}]

Crossrefs

Cf. A000010, A000203, A055234.

Sequence in context: A173992 A027600 A024416 * A190586 A113225 A298539

Adjacent sequences: A076372 A076373 A076374 * A076376 A076377 A076378

Keyword

nonn

Author

Labos Elemer, Oct 15 2002

Status

approved