OFFSET
1,2
COMMENTS
Let b(1)=x, b(2)=y, k*b(k)=(2k-1)*b(k-1) + 3(k+1)*b(k-2); then b(n)=c(n)*x+a(n)/3*y.
FORMULA
a(1)=0; a(n+1) = 3*a(n)-(-1)^n*(n+2); a(n)=floor((11/48)*3^n+(-1)^n*n/4+1/2)
MATHEMATICA
CoefficientList[Series[x^2(3+2x)/(1-x-5x^2-3x^3), {x, 0, 30}], x] (* Harvey P. Dale, Nov 23 2018 *)
PROG
(PARI) a(n)=if(n<0, 0, polcoeff(x^2*(3+2*x)/(1-x-5*x^2-3*x^3)+x*O(x^n), n))
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Nov 02 2002
STATUS
approved