a(n) = (n+1)*Sum_{i=0..n/2}((binomial(n-i,i))*binomial(2*(n-2*i),(n-2*i))/(n-2*i+1)^2).

A270595

a(n) = (n+1)*Sum_{i=0..n/2}((binomial(n-i,i))*binomial(2*(n-2*i),(n-2*i))/(n-2*i+1)^2).

Terms

    a(0) =1a(1) =1a(2) =5a(3) =9a(4) =29a(5) =81a(6) =265a(7) =881a(8) =3065a(9) =10897a(10) =39533a(11) =145561a(12) =542645a(13) =2043745a(14) =7764497a(15) =29719521a(16) =114495985a(17) =443623521a(18) =1727552085a(19) =6757763753a(20) =26541775821a(21) =104626427441a(22) =413800025625

External references