A025574 T(2n,n+1), where T is the array defined in A025564.

1, 10, 61, 356, 2058, 11892, 68860, 399828, 2328066, 13591364, 79538750, 466489520, 2741310614, 16137748980, 95152639095, 561856988100, 3322001296650, 19664909435556, 116535288360106, 691284470658376, 4104450497833036, 24390520567203960, 145053186645586383

Offset

1,2

Comments

Coefficient of y^(n+1) in (y^2+2*y+1)*(y^2+y+1)^(2*n-2). - Robert Israel, Sep 07 2019

Links

Robert Israel, Table of n, a(n) for n = 1..1278

Maple

f:= n -> coeff((y^2+2*y+1)*(y^2+y+1)^(2*n-2), y, n+1);
map(f, [$1..30]); # Robert Israel, Sep 07 2019

Crossrefs

Cf. A025564.

Sequence in context: A361535 A271790 A319965 * A301383 A321386 A015867

Adjacent sequences: A025571 A025572 A025573 * A025575 A025576 A025577

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Sep 07 2019

Status

approved