OFFSET
0,4
LINKS
Index entries for linear recurrences with constant coefficients, signature (-2,9,2,-8).
FORMULA
G.f. : x(1+2x)/((1-x^2)(1+2x-8x^2));
a(n)=4*2^n/9-4(-4)^n/45-(-1)^n/18-3/10;
a(n)=(13-4*J(2n+1))(-1)^n/30+4*J(n)/3-3/10, J(n)=A001045(n);
a(n)=sum{k=0..n (-1)^(k+1)*J(k)^2};
MATHEMATICA
LinearRecurrence[{-2, 9, 2, -8}, {0, 1, 0, 9}, 30] (* Harvey P. Dale, Feb 13 2018 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Mar 07 2008
STATUS
approved