OFFSET
3,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 3..1000
Index entries for linear recurrences with constant coefficients, signature (24,-260,1680,-7206,21600,-46364,71760,-79441,61320,-31320,9504,-1296).
FORMULA
E.g.f.: x^3/3! * Sum_{j=0..3} Stirling2(3,j)*exp(x)^j.
a(n) = C(n,3) * Sum_{j=0..3} Stirling2(3,j) * j^(n-3).
G.f.: x^3*(5 - 80*x + 560*x^2 - 2240*x^3 + 5620*x^4 - 9120*x^5 + 9428*x^6 - 5712*x^7 + 1555*x^8)/((1 - x)*(1 - 2*x)*(1 - 3*x))^4. - Andrew Howroyd, Oct 31 2025
MAPLE
a:= n-> binomial(n, 3)*add(Stirling2(3, j)*j^(n-3), j=0..3):
seq(a(n), n=3..40);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 27 2016
STATUS
approved