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%I #11 May 22 2013 02:54:04
%S 1,3,35,99,227,2275,6371,14563,145635,407779,932067,9320675,26097891,
%T 59652323,596523235,1670265059,3817748707,38177487075,106896963811,
%U 244335917283,2443359172835,6841405683939,15637498706147
%N a(n) = sum(2^(A047240(i)-1), i=1..n).
%H Vincenzo Librandi, <a href="/A113854/b113854.txt">Table of n, a(n) for n = 1..300</a>
%F G.f.: x*(1+2*x+32*x^2)/((-1+x)*(-1+4*x)*(1+4*x+16*x^2)). - _Vaclav Kotesovec_, Nov 28 2012
%e a(2) = 2^(A047240(1)-1) + 2^(A047240(2)-1) = 2^0 + 2^1 = 3
%t a = {}; s = 0; For[n = 1, n < 48, n++, If[Length[Intersection[{Mod[n, 6]}, {1, 2, 0}]] > 0, s = s + 2^(n - 1); AppendTo[a, s]]]; a
%t CoefficientList[Series[(1 + 2 x + 32 x^2)/((-1 + x) (-1 + 4 x) (1 + 4 x + 16 x^2)), {x, 0, 25}], x] (* _Vincenzo Librandi_, May 20 2013 *)
%Y Cf. A047240.
%K nonn,easy
%O 1,2
%A _Artur Jasinski_, Jan 27 2006
%E Edited by _Stefan Steinerberger_, Jul 24 2007
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