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%I #7 Jan 28 2023 12:08:36
%S 1,2,4,6,7,8,10,11,12,14,16,18,19,20,22,24,26,27,28,30,31,32,34,35,36,
%T 38,40,42,43,44,46,47,48,50,51,52,54,56,58,59,60,62,64,66,67,68,70,72,
%U 74,75,76,78,79,80,82,83,84,86,88,90,91,92,94,96,98,99,100
%N Increasing sequence: "if n appears then a*n+b doesn't", case a(1)=1, a=2, b=1.
%C A positive integer n is in A121538 iff any of the following is true: 1) n is even; 2) n+1 = 2^k where k is odd; 3) n+1 = 2^k*(2*t+1) where t>0 and k is even. - _Max Alekseyev_, Aug 07 2006
%F This is essentially A053661-1. - _David W. Wilson_, Aug 07 2006
%t s={s1=1};With[{a=2,b=1},Do[If[FreeQ[s,(n-b)/a],AppendTo[s,n]],{n,s1+1,100}]];s
%Y Cf. A121539, A121540, A121541, A121542.
%K nonn
%O 1,2
%A _Zak Seidov_, Aug 06 2006