OFFSET
1,1
LINKS
P. Moree, Convoluted convolved Fibonacci numbers
Index entries for linear recurrences with constant coefficients, signature (2,-1,1,-2,1).
FORMULA
G.f.: x(x^4-2x^3-x+3)/[(1-x^3)(1-x)^2].
9*a(n) = 11 +27*n/2 +3*n^2/2 -A099837(n+3). - R. J. Mathar, Jan 09 2024
MAPLE
with(numtheory): f := z->1/(1-z-z^2): m := proc(r, j) d := divisors(r): W := (1/r)*z*sum(mobius(d[i])*f(z^d[i])^(r/d[i]), i=1..nops(d)): Wser := simplify(series(W, z=0, 80)): coeff(Wser, z^j) end: seq(m(r, 4), r=1..60);
MATHEMATICA
LinearRecurrence[{2, -1, 1, -2, 1}, {3, 5, 7, 10, 13}, 60] (* Jean-François Alcover, Nov 28 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 05 2003
EXTENSIONS
Edited by Emeric Deutsch, Mar 06 2004
STATUS
approved