A026661 T(2n,n-1), T given by A026659.

1, 5, 20, 87, 358, 1533, 6445, 27555, 117529, 503001, 2167209, 9289047, 40320051, 173069913, 755481768, 3247042719, 14236984102, 61259521341, 269560841080, 1161017915091, 5123885956516, 22087793150253, 97719510829418

Offset

1,2

Links

Table of n, a(n) for n=1..23.

Crossrefs

Sequence in context: A045499 A358518 A145932 * A099014 A219672 A011966

Adjacent sequences: A026658 A026659 A026660 * A026662 A026663 A026664

Keyword

nonn

Author

Clark Kimberling

Status

approved