A022041 a(n) = 3*a(n-1)+a(n-2)-a(n-3)+a(n-6)-a(n-7)+a(n-10)-a(n-11).

2, 6, 19, 61, 196, 630, 2026, 6516, 20957, 67403, 216786, 697242, 2242518, 7212542, 23197478, 74609338, 239963729, 771787993, 2482278087, 7983674995, 25677649398, 82586237418, 265619586324, 854304141280, 2747672247776

Offset

0,1

Links

Table of n, a(n) for n=0..24.

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

Formula

G.f.: (2-x^10-x^6-x^2)/(1+x^11-x^10+x^7-x^6+x^3-x^2-3*x). - Maksym Voznyy (voznyy(AT)mail.ru), Aug 11 2009

Prog

(PARI) a(n)=([0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1; -1, 1, 0, 0, -1, 1, 0, 0, -1, 1, 3]^n*[2; 6; 19; 61; 196; 630; 2026; 6516; 20957; 67403; 216786])[1, 1] \\ Charles R Greathouse IV, Jun 01 2026

Crossrefs

Different from A014010.

Sequence in context: A318127 A001169 A187276 * A018906 A014010 A022015

Adjacent sequences: A022038 A022039 A022040 * A022042 A022043 A022044

Keyword

nonn,easy,changed

Author

R. K. Guy

Extensions

Corrected by Franklin T. Adams-Watters, Oct 25 2006

Status

approved