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A190984
a(n) = 9*a(n-1) - 7*a(n-2), with a(0)=0, a(1)=1.
7
0, 1, 9, 74, 603, 4909, 39960, 325277, 2647773, 21553018, 175442751, 1428113633, 11624923440, 94627515529, 770273175681, 6270065972426, 51038681522067, 415457671891621, 3381848276370120, 27528430784089733, 224082939122216757, 1824047436611322682
OFFSET
0,3
FORMULA
G.f.: x/(1-9*x+7*x^2). - Philippe Deléham, Oct 12 2011
E.g.f.: (2/sqrt(53))*exp(9*x/2)*sinh(sqrt(53)*x/2). - G. C. Greubel, Aug 26 2022
MATHEMATICA
LinearRecurrence[{9, -7}, {0, 1}, 50]
PROG
(Magma) [Round(7^((n-1)/2)*Evaluate(ChebyshevU(n), 9/(2*Sqrt(7)))): n in [0..30]]; // G. C. Greubel, Aug 26 2022
(SageMath)
A190984 = BinaryRecurrenceSequence(9, -7, 0, 1)
[A190984(n) for n in (0..30)] # G. C. Greubel, Aug 26 2022
CROSSREFS
Cf. A190958 (index to generalized Fibonacci sequences).
Sequence in context: A319961 A037533 A178827 * A001716 A372843 A231910
KEYWORD
nonn
AUTHOR
STATUS
approved