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%I #17 Dec 11 2023 08:39:03
%S 6,26,30,32,34,36,46,56,106,126,130,132,134,136,146,150,152,154,160,
%T 162,164,170,172,174,176,180,182,184,186,196,226,230,232,234,236,246,
%U 256,276,280,282,284,286,296,306,356,506,526,530
%N Numbers whose base-5 representation contains exactly two 1's and no 3's.
%H Robert Israel, <a href="/A045240/b045240.txt">Table of n, a(n) for n = 1..10000</a>
%p A0[1]:= {2,4}:
%p A1[1]:= {1}:
%p A11[1]:= {}:
%p count:= 0:
%p for n from 2 while count < 1000 do
%p A0[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A0[n-1]);
%p A1[n]:= map(t -> (5*t,5*t+2,5*t+4), A1[n-1]) union map(t -> 5*t+1, A0[n-1]);
%p A11[n]:= map(t -> (5*t,5*t+2,5*t+4), A11[n-1]) union map(t -> 5*t+1, A1[n-1]);
%p count:= count + nops(A11[n]);
%p od:
%p sort([seq(op(A11[i]),i=1..n-1)]); # _Robert Israel_, Dec 10 2023
%Y Cf. A007091.
%K nonn,base
%O 1,1
%A _Clark Kimberling_
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