a(n) = ((n+2)/2)*Sum_{k=0..n/2} (Sum_{i=0..n-2*k} (binomial(k+1,n-2*k-i)*binomial(k+i,k))/(k+1)*C(k)), where C(k) is Catalan numbers.

A270724

a(n) = ((n+2)/2)*Sum_{k=0..n/2} (Sum_{i=0..n-2*k} (binomial(k+1,n-2*k-i)*binomial(k+i,k))/(k+1)*C(k)), where C(k) is Catalan numbers.

Terms

    a(0) =1a(1) =3a(2) =5a(3) =10a(4) =20a(5) =42a(6) =93a(7) =213a(8) =504a(9) =1221a(10) =3014a(11) =7553a(12) =19158a(13) =49087a(14) =126845a(15) =330174a(16) =864884a(17) =2278138a(18) =6030218a(19) =16031950a(20) =42790362a(21) =114616360a(22) =307996874a(23) =830084080a(24) =2243193198a(25) =6076953906a(26) =16500486744a(27) =44897830740a(28) =122406923038a(29) =334333367602

External references