A257956 Row sums of A232642, when seen as a triangle read by rows.

1, 6, 24, 74, 220, 626, 1754, 4860, 13390, 36762, 100728, 275666, 753898, 2060924, 5632550, 15391650, 42056008, 114907626, 313947186, 857741852, 2343430222

Offset: 1

Author

Reinhard Zumkeller, May 14 2015

Keywords

• nonn

Comments

a(n) <= A166060(n).

Crossrefs

Cf. A232642, A166060.

Programs

Haskell

a257956 = sum . a232642_row

Formula

Conjectures from Colin Barker, May 29 2015: (Start)

a(n) = 3*a(n-1)+a(n-2)-4*a(n-3)-2*a(n-4) for n>4.

G.f.: x*(5*x^2+3*x+1) / ((x^2+x-1)*(2*x^2+2*x-1)).

(End)