A028831 Expansion of (1+2*x+3*x^2)/(1-x-x^2-x^3-x^4).

1, 3, 7, 11, 22, 43, 83, 159, 307, 592, 1141, 2199, 4239, 8171, 15750, 30359, 58519, 112799, 217427, 419104, 807849, 1557179, 3001559, 5785691, 11152278, 21496707, 41436235, 79870911, 153956131

Offset

0,2

Links

Table of n, a(n) for n=0..28.

Index entries for linear recurrences with constant coefficients, signature (1, 1, 1, 1).

Formula

a(0)=1, a(1)=3, a(2)=7, a(3)=11, a(n)=a(n-1)+a(n-2)+a(n-3)+a(n-4) [From Harvey P. Dale, Apr 18 2012]

Mathematica

CoefficientList[Series[(1+2x+3x^2)/(1-x-x^2-x^3-x^4), {x, 0, 30}], x] (* or *) LinearRecurrence[{1, 1, 1, 1}, {1, 3, 7, 11}, 30] (* Harvey P. Dale, Apr 18 2012 *)

Crossrefs

Sequence in context: A018345 A082675 A201645 * A244572 A137516 A247380

Adjacent sequences: A028828 A028829 A028830 * A028832 A028833 A028834

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved