Diagonal sums of a Chebyshev number triangle.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =10a(5) =24a(6) =64a(7) =182a(8) =542a(9) =1685a(10) =5473a(11) =18594a(12) =66063a(13) =245078a(14) =947057a(15) =3802469a(16) =15826392a(17) =68158314a(18) =303273906a(19) =1392503108a(20) =6590530876a(21) =32117814629a(22) =160998508095a(23) =829301391150