A027318 a(n) = Sum_{k=0..m-3} T(n,k) * T(n,k+2), where m=n for n=0,1,2,3; m=2n for n >= 4; and T is given by A026082.

1, 42, 420, 3786, 33648, 297940, 2633872, 23265744, 205446960, 1814136746, 16021697220, 141535810130, 1250763720312, 11057433981126, 97794407702052, 865284559977150, 7659315417653664, 67827407480624862, 600898634852988364, 5325658497658529790

Offset

3,2

Links

Table of n, a(n) for n=3..22.

Crossrefs

Sequence in context: A114928 A364943 A127545 * A251425 A242144 A242145

Adjacent sequences: A027315 A027316 A027317 * A027319 A027320 A027321

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Oct 27 2019

Status

approved