OFFSET
0,2
COMMENTS
a(n) is the number of generalized compositions of n when there are i+2 different types of i, (i=1,2,...). [Milan Janjic, Sep 24 2010]
LINKS
P. J. Cameron, Some sequences of integers, Discrete Math., 75 (1989), 89-102.
P. J. Cameron, Some sequences of integers, in "Graph Theory and Combinatorics 1988", ed. B. Bollobas, Annals of Discrete Math., 43 (1989), 89-102.
Index entries for linear recurrences with constant coefficients, signature (5,-3).
FORMULA
a(n+2) = 5a(n+1) - 3a(n) (n >= 1); a(0) = 1, a(1) = 3, a(2) = 13.
MATHEMATICA
CoefficientList[Series[(1-x)^2/(1-5x+3x^2), {x, 0, 30}], x] (* or *) LinearRecurrence[{5, -3}, {1, 3, 13}, 30] (* Harvey P. Dale, Jun 21 2021 *)
PROG
(PARI) a(n)=polcoeff((1-x)^2/(1-5*x+3*x^2)+x*O(x^n), n)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jul 13 2004
STATUS
approved