OFFSET
0,2
COMMENTS
Lies to the right of the y-axis of the triangle.
Binomial transform of (1, 12, 9, 0, 0, 0, ...).
LINKS
FORMULA
G.f.: (1 + 10*x - 2*x^2)/(1 - x)^3.
a(n) = binomial(n,0) + 12*binomial(n,1) + 9*binomial(n,2).
a(n) = (9*n^2 + 15*n + 2)/2.
a(0) = 1, a(n) = a(n-1) + 9*n + 3 for n > 0 - Gerald McGarvey, Aug 18 2004
From Elmo R. Oliveira, Oct 25 2024: (Start)
E.g.f.: exp(x)*(1 + 12*x + 9*x^2/2).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 2. (End)
PROG
(PARI) a(n)=(9*n^2+15*n+2)/2 \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Mar 15 2003
STATUS
approved