OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..500
Index entries for linear recurrences with constant coefficients, signature (20, -98).
FORMULA
a(n) = ((2+sqrt(2))*(10+sqrt(2))^n + (2-sqrt(2))*(10-sqrt(2))^n)/4.
G.f.: (1-9*x)/(1-20*x+98*x^2).
E.g.f.: (1/2)*exp(10*x)*( 2*cosh(sqrt(2)*x) + sqrt(2)*sinh(sqrt(2)*x) ). - G. C. Greubel, Dec 25 2016
MATHEMATICA
LinearRecurrence[{20, -98}, {1, 11}, 30] (* Harvey P. Dale, Dec 04 2011 *)
CoefficientList[Series[(1 - 9 x)/(1 - 20 x + 98 x^2), {x, 0, 17}], x] (* Michael De Vlieger, Dec 25 2016 *)
PROG
(Magma) [ n le 2 select 10*n-9 else 20*Self(n-1)-98*Self(n-2): n in [1..18] ];
(PARI) Vec((1-9*x)/(1-20*x+98*x^2) + O(x^50)) \\ G. C. Greubel, Dec 25 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Jul 28 2009
STATUS
approved