OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..3000
Index entries for linear recurrences with constant coefficients, signature (5,-8,4).
FORMULA
a(n) = 2^(n-1)*(n+20) - 9.
a(n) = 5*a(n-1) - 8*a(n-2) + 4*a(n-3), a(0)=1, a(1)=12, a(2)=35.
G.f.: (1+7*x-17*x^2)/((1-x)*(1-2*x)^2). - Colin Barker, Aug 24 2016
E.g.f.: exp(x)*(exp(x)*(10 + x) - 9). - Elmo R. Oliveira, Oct 28 2025
MATHEMATICA
LinearRecurrence[{5, -8, 4}, {1, 12, 35}, 40] (* Harvey P. Dale, Jul 24 2019 *)
PROG
(Magma) [2^(n-1)*(n+20)-9: n in [0..30]]; // Vincenzo Librandi, Sep 28 2011
(PARI) Vec((1+7*x-17*x^2)/((1-x)*(1-2*x)^2) + O(x^40)) \\ Colin Barker, Aug 24 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Sep 28 2011
STATUS
approved