A131857 Numbers m such that A131852(m) = 1.

2, 3, 6, 7, 18, 19, 22, 23, 32, 33, 36, 37, 42, 43, 46, 47, 48, 49, 52, 53, 58, 59, 62, 63, 66, 67, 70, 71, 82, 83, 86, 87, 96, 97, 100, 101, 106, 107, 110, 111, 112, 113, 116, 117, 122, 123, 126, 127, 162, 163, 166, 167, 178, 179, 182, 183, 226, 227, 230, 231, 242, 243

Offset: 1

Author

Reinhard Zumkeller, Jul 22 2007

Keywords

• nonn

Links

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

Crossrefs

Cf. A131856, A131854, A131855, A131862, A131864.

Programs

Maple

Z:= proc(n) option remember;
I*procname(floor(n/2))+(n mod 2)
end proc:
Z(0):= 0:
select(Im@Z=1, [$0..1000]); # Robert Israel, Dec 18 2017

Mathematica

z[0] = 0; z[n_] := z[n] = z[Floor[n/2]]*I + Mod[n, 2]; Select[Range[0, 250], Im[z[#]] == 1&] (* Jean-François Alcover, Jan 31 2018 *)

PARI

isok(n) = {d = Vecrev(binary(n)); imag(sum(k=1, #d, d[k]*I^(k-1))) == 1;} \\ Michel Marcus, Jan 31 2018