OFFSET
0,4
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
László Németh, Hyperbolic Pascal pyramid, arXiv:1511.0267 [math.CO], 2015 (2nd line of Table 2).
Index entries for linear recurrences with constant coefficients, signature (5,-6,2).
FORMULA
a(n) = 5*a(n-1) - 6*a(n-2) + 2*a(n-3), n >= 4.
From Colin Barker, Sep 17 2017: (Start)
G.f.: 6*x^3 / ((1 - x)*(1 - 4*x + 2*x^2)).
a(n) = (1/2)*(-12 + (9-6*sqrt(2))*(2+sqrt(2))^n + (2-sqrt(2))^n*(9+6*sqrt(2))) for n>0.
(End)
MATHEMATICA
CoefficientList[Series[6*x^3/((1 - x)*(1 - 4*x + 2*x^2)), {x, 0, 30}],
x] (* Wesley Ivan Hurt, Sep 17 2017 *)
PROG
(PARI) concat(vector(3), Vec(6*x^3 / ((1 - x)*(1 - 4*x + 2*x^2)) + O(x^30))) \\ Colin Barker, Sep 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric M. Schmidt, Sep 14 2017
STATUS
approved