OFFSET
1,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..800
Index entries for linear recurrences with constant coefficients, signature (2, 121).
FORMULA
a(n) = 2*a(n-1) + 121*a(n-2).
a(n) = (11*i)^(n-2)*ChebyshevU(n-2, -i/11). - G. C. Greubel, Jul 12 2021
MATHEMATICA
Rest@CoefficientList[Series[x^2/(1 -2*x -121*x^2), {x, 0, 30}], x]
PROG
(Magma) [n le 2 select n-1 else 2*Self(n-1) + 121*Self(n-2): n in [1..30]]; // G. C. Greubel, Jul 12 2021
(Sage) [(11*i)^(n-2)*chebyshev_U(n-2, -i/11) for n in [1..30]] # G. C. Greubel, Jul 12 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula and Gary W. Adamson, Sep 23 2006
STATUS
approved