A190984 a(n) = 9*a(n-1) - 7*a(n-2), with a(0)=0, a(1)=1.

0, 1, 9, 74, 603, 4909, 39960, 325277, 2647773, 21553018, 175442751, 1428113633, 11624923440, 94627515529, 770273175681, 6270065972426, 51038681522067, 415457671891621, 3381848276370120, 27528430784089733, 224082939122216757, 1824047436611322682

Offset: 0

Author

Vladimir Joseph Stephan Orlovsky, May 24 2011

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (9,-7).

Crossrefs

Cf. A190958 (index to generalized Fibonacci sequences).

Programs

Magma

[Round(7^((n-1)/2)*Evaluate(ChebyshevU(n), 9/(2*Sqrt(7)))): n in [0..30]]; // G. C. Greubel, Aug 26 2022

Mathematica

LinearRecurrence[{9,-7}, {0,1}, 50]

SageMath

A190984 = BinaryRecurrenceSequence(9,-7,0,1)
[A190984(n) for n in (0..30)] # G. C. Greubel, Aug 26 2022

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