login
A167478
Expansion of (1-2x+6x^2-x^3)/(1-3x+x^2)^2.
2
1, 4, 19, 75, 264, 869, 2741, 8396, 25175, 74271, 216336, 623689, 1782889, 5060500, 14277019, 40070259, 111954456, 311555501, 863978525, 2388417116, 6584117471, 18104432199, 49667825184, 135974484625, 371543306449, 1013443026724
OFFSET
0,2
COMMENTS
Hankel transform of A054109.
FORMULA
G.f.: (1-2*x+6*x^2-x^3)/(1-3*x+x^2)^2.
a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) - a(n-4). - Wesley Ivan Hurt, Jul 28 2022
MATHEMATICA
LinearRecurrence[{6, -11, 6, -1}, {1, 4, 19, 75}, 100] (* G. C. Greubel, Jun 13 2016 *)
CoefficientList[Series[(1-2x+6x^2-x^3)/(1-3x+x^2)^2, {x, 0, 30}], x] (* Harvey P. Dale, Aug 04 2018 *)
CROSSREFS
Cf. A054109.
Sequence in context: A009450 A096978 A186810 * A094734 A094578 A130132
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Nov 04 2009
STATUS
approved