OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (4,0,-8,4).
FORMULA
G.f.: (1-3x+2x^3)/(1-4x+8x^3-4x^4);
e.g.f.: exp(x)cosh(x)cosh(sqrt(2)x);
a(n) = ((sqrt(2))^n + (-sqrt(2))^n + (2+sqrt(2))^n + (2-sqrt(2))^n)/4.
MATHEMATICA
LinearRecurrence[{4, 0, -8, 4}, {1, 1, 4, 10}, 30] (* Harvey P. Dale, Jun 16 2017 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Sep 18 2003
STATUS
approved