A373006 - OEIS

%I #7 May 27 2024 15:48:00

%S 1,2,6,10,20,41,84,162,324,637,1276,2509,5018,9907,19816,39202,78404,

%T 155381,310764,616665,1233330,2449867,4899736,9740685,19481370,

%U 38754731,77509464,154276027,308552054,614429671,1228859344,2448023842,4896047684,9756737701,19513475404

%N Antidiagonal sums of A373005.

%F Limit_{n->oo} a(n)/a(n-1) = 2.

%t A373005[n_,k_]:=If[OddQ[k],Sum[Binomial[n,i],{i,0,(k-1)/2}],Sum[Binomial[n,i],{i,0,k/2-1}]+Binomial[n-1,k/2-1]]; a[n_]:=Sum[A373005[n-k,n],{k,0,n}]; Array[a,35,0]

%Y Cf. A000079, A373005.

%K nonn

%O 0,2

%A _Stefano Spezia_, May 19 2024