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

Author

Clark Kimberling

Keywords

• nonn

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

Crossrefs

Cf. A025564.

Programs

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

Extensions

More terms from Sean A. Irvine, Sep 07 2019