OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,6,-4,-5,1,1).
FORMULA
G.f.: (x^2 + x - 1) / (x^6 + x^5 - 5*x^4 - 4*x^3 + 6*x^2 + 3*x - 1). - Colin Barker, Jun 14 2013
a(n) = 3*a(n-1) + 6*a(n-2) - 4*a(n-3) - 5*a(n-4) + a(n-5) + a(n-6). - Wesley Ivan Hurt, Oct 09 2017
MAPLE
a:= n-> (Matrix(6, (i, j)->`if`(i+j>7, 0, 1))^n.<<[1$6][]>>)[5, 1]:
seq(a(n), n=0..30); # Alois P. Heinz, Jun 14 2013
MATHEMATICA
CoefficientList[Series[(x^2 + x - 1)/(x^6 + x^5 - 5*x^4 - 4*x^3 + 6*x^2 + 3*x - 1), {x, 0, 30}], x] (* Wesley Ivan Hurt, Oct 09 2017 *)
LinearRecurrence[{3, 6, -4, -5, 1, 1}, {1, 2, 11, 41, 176, 721}, 30] (* Vincenzo Librandi, Oct 10 2017 *)
PROG
(Magma) I:=[1, 2, 11, 41, 176, 721]; [n le 6 select I[n] else 3*Self(n-1)+6*Self(n-2)-4*Self(n-3)-5*Self(n-4)+Self(n-5)+Self(n-6): n in [1..30]]; // Vincenzo Librandi, Oct 10 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Henry Bottomley, May 06 2002
STATUS
approved