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

%I A131857 #11 Jan 31 2018 03:58:09
%S A131857 2,3,6,7,18,19,22,23,32,33,36,37,42,43,46,47,48,49,52,53,58,59,62,63,
%T A131857 66,67,70,71,82,83,86,87,96,97,100,101,106,107,110,111,112,113,116,
%U A131857 117,122,123,126,127,162,163,166,167,178,179,182,183,226,227,230,231,242,243
%N A131857 Numbers m such that A131852(m) = 1.
%H A131857 Robert Israel, <a href="/A131857/b131857.txt">Table of n, a(n) for n = 1..10000</a>
%p A131857 Z:= proc(n) option remember;
%p A131857 I*procname(floor(n/2))+(n mod 2)
%p A131857 end proc:
%p A131857 Z(0):= 0:
%p A131857 select(Im@Z=1, [$0..1000]); # _Robert Israel_, Dec 18 2017
%t A131857 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 *)
%o A131857 (PARI) isok(n) = {d = Vecrev(binary(n)); imag(sum(k=1, #d, d[k]*I^(k-1))) == 1;} \\ _Michel Marcus_, Jan 31 2018
%Y A131857 Cf. A131856, A131854, A131855, A131862, A131864.
%K A131857 nonn
%O A131857 1,1
%A A131857 _Reinhard Zumkeller_, Jul 22 2007