A177467 Expansion of g.f. (1+2*x+3*x^2)/(1-3*x-14*x^2+15*x^3+7*x^4).

1, 5, 32, 151, 819, 4056, 21145, 106877, 550088, 2800975, 14352987, 73273152, 374896033, 1915610597, 9795808064, 50069619991, 255991741683, 1308603509784, 6690079956601, 34200325541597, 174841101178664, 893816437200847, 4569389285283675, 23359579180191744, 119419053268283329

Offset

0,2

Links

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

Alexander Burstein, Sergey Kitaev, and Toufik Mansour. Counting independent sets in certain classes of (almost) regular graphs, Pure Mathematics and Applications (PU.M.A.) 19 (2008), no. 2-3, 17-26.

Index entries for linear recurrences with constant coefficients, signature (3,14,-15,-7).

Formula

a(n) = 3*a(n-1) + 14*a(n-2) - 15*a(n-3) - 7*a(n-4) for n > 4. - Chai Wah Wu, Dec 24 2023

Mathematica

 CoefficientList[Series[(1+2*x+3*x^2)/(1-3*x-14*x^2+15*x^3+7*x^4), {x, 0, 50}
], x] (* Georg Fischer, Jan 19 2024 *)

Crossrefs

Sequence in context: A359522 A001589 A271903 * A268153 A271153 A272540

Adjacent sequences: A177464 A177465 A177466 * A177468 A177469 A177470

Keyword

nonn,easy

Author

Signy Olafsdottir (signy06(AT)ru.is), May 09 2010

Extensions

More terms from Stefano Spezia, Dec 24 2023

Offset changed to 0 by Georg Fischer, Jan 19 2024

Status

approved