OFFSET
1,2
LINKS
Colin Barker, Table of n, a(n) for n = 1..997
Index entries for linear recurrences with constant coefficients, signature (8,21).
FORMULA
Limit_{n -> oo} a(n+1)/a(n) converges to 4 + sqrt(37).
G.f.: x*(1+3*x)/(1-8*x-21*x^2). - Colin Barker, May 22 2015
MATHEMATICA
LinearRecurrence[{8, 21}, {1, 11}, 41] (* G. C. Greubel, Feb 09 2023 *)
PROG
(PARI) Vec(x*(1+3*x)/(1-8*x-21*x^2) + O(x^40)) \\ Colin Barker, May 22 2015
(Magma) [n le 2 select 10*n-9 else 8*Self(n-1) +21*Self(n-2): n in [1..41]]; // G. C. Greubel, Feb 09 2023
(SageMath)
@CachedFunction
def a(n): # a = A094703
if (n<3): return 10*n-9
else: return 8*a(n-1) + 21*a(n-2)
[a(n) for n in range(1, 41)] # G. C. Greubel, Feb 09 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, May 21 2004
EXTENSIONS
More terms from Robert G. Wilson v, May 24 2004
Edited by Don Reble, Nov 04 2005
STATUS
approved