%I #6 Mar 30 2012 18:59:51
%S 1,2,7,4,21,6,43,8,73,10,111,12,157,14,211,16,273,18,343,20,421,22,
%T 507,24,601,26,703,28,813,30,931,32,1057,34,1191,36,1333,38,1483,40,
%U 1641,42,1807,44,1981,46,2163,48,2353,50,2551,52,2757,54,2971,56,3193
%N a(2*n) = 2*n and a(2*n-1) = A054569(n).
%C Equals the Row2 triangle sums of the Connell sequence A001614 as a triangle. The Row2(n) triangle sums are defined by Row2(n) = sum((-1)^(n+k)*T(n,k), k=1..n), see A180662.
%F a(2*n) = 2*n and a(2*n-1) = 4*n^2 - 6*n + 3
%F G.f.: x*(1+2*x+4*x^2-2*x^3+3*x^4)/(1-x^2)^3
%p A190716:= n-> coeff (series (x*(1+2*x+4*x^2-2*x^3+3*x^4)/(1-x^2)^3, x, n+1), x, n): seq(A190716(n), n=1..49);
%K nonn,easy
%O 1,2
%A _Johannes W. Meijer_, May 18 2011