A026387 a(n) = number of integer strings s(0),...,s(n) counted by array T in A026386 that have s(n)=0; also a(n) = T(2n,n).

2, 8, 34, 150, 678, 3116, 14494, 68032, 321590, 1528776, 7301142, 35003238, 168359754, 812041860, 3926147730, 19022666310, 92338836390, 448968093320, 2186194166950, 10659569748370, 52037098259090, 254308709196660

Offset: 0

Author

Clark Kimberling

Keywords

• nonn
• changed

Links

• László Németh, Tetrahedron trinomial coefficient transform, arXiv:1905.13475 [math.CO], 2019.

Crossrefs

Essentially the same as A085362.

Cf. A026378.

Formula

a(n) = A085362(n+1), n >= 0. - Hartmut F. W. Hoft, Jul 07 2024