A045047 Numbers whose base-4 representation contains exactly two 0's and no 2's.

16, 48, 65, 67, 68, 76, 80, 112, 193, 195, 196, 204, 208, 240, 261, 263, 269, 271, 273, 275, 276, 284, 305, 307, 308, 316, 321, 323, 324, 332, 336, 368, 449, 451, 452, 460, 464, 496, 773, 775, 781, 783, 785, 787, 788, 796, 817

Offset

1,1

Comments

If k is in the sequence, then so are 4*k+1 and 4*k+3 but not 4*k or 4*k+2. - Robert Israel, Jan 19 2023

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

filter:= proc(n) local L; L:= convert(n, base, 4);
  not member(2, L) and numboccur(0, L)=2
end proc:
select(filter, [$1..1000]); # Robert Israel, Jan 19 2023

Crossrefs

Cf. A007090.

Sequence in context: A374588 A354181 A264164 * A239344 A195087 A348882

Adjacent sequences: A045044 A045045 A045046 * A045048 A045049 A045050

Keyword

nonn,base

Author

Clark Kimberling

Status

approved