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A113049 Triangle of sums of Jacobsthal numbers related to binomial(4n,n)/(3n+1) mod 4.

%I A113049 #3 Mar 30 2012 18:59:12
%S A113049 3,11,13,43,45,53,171,173,181,213,683,685,693,725,853,2731,2733,2741,
%T A113049 2773,2901,3413,10923,10925,10933,10965,11093,11605,13653,43691,43693,
%U A113049 43701,43733,43861,44373,46421,54613,174763,174765,174773,174805,174933
%N A113049 Triangle of sums of Jacobsthal numbers related to binomial(4n,n)/(3n+1) mod 4.
%C A113049 First column is A007583(n+1). Main diagonal is A072197. Conjecture: A113048(n)=2 only if n=T(i,j).
%F A113049 T(n, k)=if(k<=n, J(2n+3)+2J(2k), 0), J(n)=A001045(n).
%e A113049 Rows begin
%e A113049 3;
%e A113049 11, 13;
%e A113049 43, 45, 53;
%e A113049 171, 173, 181, 213;
%e A113049 683, 685, 693, 725, 683;
%e A113049 2731,2733, 2741, 2773, 2901, 3413;
%K A113049 easy,nonn,tabl
%O A113049 0,1
%A A113049 _Paul Barry_, Oct 11 2005