OFFSET
1,1
LINKS
Colin Barker, Table of n, a(n) for n = 1..750
Index entries for linear recurrences with constant coefficients, signature (0,340,0,-1).
FORMULA
G.f.: 2*x*(2 + 11*x + 11*x^2 + 2*x^3)/(1 - 340*x^2 + x^4).
a(n) = 340*a(n-2) - a(n-4), for n>3.
MATHEMATICA
LinearRecurrence[{0, 340, 0, -1}, {4, 22, 1382, 7484}, 30]
PROG
(Magma) I:=[4, 22, 1382, 7484]; [n le 4 select I[n] else 340*Self(n-2)-Self(n-4): n in [1..30]];
(PARI) x='x+O('x^99); Vec(2*x*(2+11*x+11*x^2+2*x^3)/(1-340*x^2+x^4)) \\ Altug Alkan, May 14 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, May 14 2016
STATUS
approved