OFFSET
3,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
For n>5, a(n) = 1/6 * (n^3 - 6n^2 + 23n - 48).
G.f.: x^3*(1-x+x^2)*(1+x^2-2*x^3+x^4)/(1-x)^4. [Colin Barker, Sep 09 2012]
MATHEMATICA
LinearRecurrence[{4, -6, 4, -1}, {1, 3, 8, 15, 27, 44, 67}, 50] (* Harvey P. Dale, Apr 24 2020 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved