A181658 Row sums of A181657.

1, 2, 3, 7, 8, 19, 20, 48, 49, 118, 119, 287, 288, 695, 696, 1680, 1681, 4058, 4059, 9799, 9800, 23659, 23660, 57120, 57121, 137902, 137903, 332927, 332928, 803759, 803760, 1940448, 1940449, 4684658, 4684659, 11309767, 11309768, 27304195, 27304196

Offset: 0

Author

Paul Barry, Nov 03 2010

Keywords

• easy
• nonn

Links

• Index entries for linear recurrences with constant coefficients, signature (0,3,0,-1,0,-1)

Crossrefs

Cf. A048739 (bisection).

Programs

Mathematica

CoefficientList[Series[(1+2x+x^3)/(1-3x^2+x^4+x^6),{x,0,40}],x] (* or *) LinearRecurrence[{0,3,0,-1,0,-1},{1,2,3,7,8,19},40] (* Harvey P. Dale, Mar 29 2022 *)

Formula

G.f.: (1+2x+x^3)/(1-3x^2+x^4+x^6)=(1+2x+x^3)/((1-x^2)(1-2x^2-x^4)).