A139373 Let the binary expansion of n be n = Sum_{k} 2^{r_k}, let e(n) be the number of r_k's that are even, o(n) the number that are odd; sequence lists n such that e(n) > o(n).

1, 4, 5, 7, 13, 16, 17, 19, 20, 21, 22, 23, 25, 28, 29, 31, 37, 49, 52, 53, 55, 61, 64, 65, 67, 68, 69, 70, 71, 73, 76, 77, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 97, 100, 101, 103, 109, 112, 113, 115, 116, 117, 118, 119, 121, 124

Offset: 1

Author

Nadia Heninger and N. J. A. Sloane, Jun 07 2008

Keywords

• nonn

Comments

e(n)+o(n) = A000120(n), the binary weight of n. For e(n) = o(n) see A039004.

Crossrefs

Cf. A000120, A139351, A139352, A139353, A139354, A139355.

Cf. A039004, A139370, A139371, A139372.

Programs

Fortran

c See link in A139351

Mathematica

aQ[n_] := Module[{d = Reverse[IntegerDigits[n,2]]}, Total@d[[1;;-1;;2]] > Total@d[[2;;-1;;2]]]; Select[Range[180], aQ] (* Amiram Eldar, Dec 15 2018 *)

PARI

isok(n) = {my(irb = Vec(select(x->(x%2), Vecrev(binary(n)), 1))); #select(x->(x%2), irb) > #irb/2;} \\ Michel Marcus, Dec 15 2018