OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (6,-11,6).
FORMULA
a(n) = 5*a(n-1) - 6*a(n-2) - 24 for n > 2.
a(n) = Sum_{k=0..3} (-1)^k * k! * binomial(3,k) * Stirling2(n,k).
a(n) = Sum_{k=0..3} (-1)^k * 2^(3-k) * binomial(3,k) * k^n.
G.f.: (1-4*x) * (1-5*x+12*x^2)/((1-x) * (1-2*x) * (1-3*x)).
a(n) = 3*2^(n+1) - 3^n - 12 for n > 0. - Stefano Spezia, Oct 27 2024
a(0) = 1; a(n) = Sum_{k=1..n} (1 - 4 * k/n) * binomial(n,k) * a(n-k). - Seiichi Manyama, Oct 27 2024
PROG
(PARI) a(n) = sum(k=0, 3, (-1)^k*k!*binomial(3, k)*stirling(n, k, 2));
(PARI) a(n) = sum(k=0, 3, (-1)^k*2^(3-k)*binomial(3, k)*k^n);
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Seiichi Manyama, Oct 27 2024
STATUS
approved