A026305 a(n) = T(2n,n-1), where T is the array in A026300.

1, 4, 20, 104, 560, 3080, 17199, 97120, 553146, 3171860, 18288127, 105922544, 615820400, 3591858480, 21008159700, 123169357728, 723659556026, 4259672761560, 25115352874780, 148302374872080, 876876653336922, 5191051724957736

Offset

1,2

Links

Table of n, a(n) for n=1..22.

Crossrefs

Sequence in context: A089382 A291089 A192619 * A195256 A131786 A061709

Adjacent sequences: A026302 A026303 A026304 * A026306 A026307 A026308

Keyword

nonn

Author

Clark Kimberling

Status

approved