%I A115420
%S A115420 16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,48,49,50,51,52,53,54,
%T A115420 55,56,57,58,59,60,61,62,63,80,81,82,83,84,85,86,87,88,89,90,91,92,93,
%U A115420 94,95,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127
%N A115420 Numbers having a 1 in position 4 of their binary expansion.
%C A115420 One of the mystery calculator sequences: A005408, A042964, A047566, A115419, 
               A115420, A115421.
%H A115420 Maths Magic, <a href="http://www.mathsyear2000.org/explorer/mathsmagic/
               realmystery/">Mystery Calculator</a>.
%e A115420 a(1) = 16 = 010000 in binary.
%Y A115420 Cf. A005408, A042964, A047566, A115419, A115421.
%Y A115420 Sequence in context: A070575 A004505 A004457 this_sequence A145449 A138599 
               A007636
%Y A115420 Adjacent sequences: A115417 A115418 A115419 this_sequence A115421 A115422 
               A115423
%K A115420 base,easy,nonn
%O A115420 1,1
%A A115420 Jeremy Gardiner (jeremy.gardiner(AT)btinternet.com), Jan 22 2006