A027021 - OEIS

%I #5 Mar 30 2012 18:56:13

%S 1,1,6,7,36,56,181,317,826,1531,3576,6832,15021,29201,61966,121727,

%T 252796,499816,1024101,2033077,4130226,8220851,16609456,33115232,

%U 66669661,133067881,267285606,533860567,1070731476,2139602456

%N a(n) = T(n,n) + T(n,m+1) + ... + T(n,n), where m=[ (n+2)/2 ], T given by A027011.

%F G.f.: x(-4x^6+10x^4-x^3-x+1)/[(1-x^2)(1-2x)(1+x-x^2)(1-x-x^2)].

%K nonn

%O 1,3

%A _Clark Kimberling_