A045889 Partial sums of A045618.

1, 7, 30, 102, 303, 825, 2116, 5200, 12381, 28779, 65658, 147594, 327835, 721069, 1573056, 3408084, 7340265, 15728895, 33554710, 71303470, 150995271, 318767457, 671089020, 1409286552, 2952790453, 6174015955, 12884902386

Offset

0,2

Links

Table of n, a(n) for n=0..26.

Formula

a(n) = (n^2+11*n+34)/2 + (n-2)*2^(n+3).

G.f.: 1/((1-2*x)^2*(1-x)^3).

a(n) = Sum_{k=1..n+4} Sum_{i=1..n+4} (i-k) * C(n-k+4,i). - Wesley Ivan Hurt, Sep 19 2017

Mathematica

Table[(n^2 + 11 n + 34)/2 + (n - 2)*2^(n + 3), {n, 0, 26}] (* or *)
CoefficientList[Series[1/((1 - 2 x)^2*(1 - x)^3), {x, 0, 26}], x] (* Michael De Vlieger, Sep 21 2017 *)

Prog

(PARI) Vec(1/((1-2*x)^2*(1-x)^3) + O(x^40)) \\ Michel Marcus, Sep 20 2017

Crossrefs

Cf. A045618.

Sequence in context: A256225 A339196 A232093 * A038739 A038798 A276289

Adjacent sequences: A045886 A045887 A045888 * A045890 A045891 A045892

Keyword

easy,nonn

Author

Wolfdieter Lang

Status

approved