OFFSET
0,2
COMMENTS
Row sums of triangle A131873.
LINKS
FORMULA
Binomial transform of (1, 11, 7, 0, 0, 0, ...).
a(n) = a(n-1) + 7*n + 4, (with a(0)=1). - Vincenzo Librandi, Nov 23 2010
a(n) = (2 + 15*n + 7*n^2)/2;
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3);
G.f.: (1 + 9*x - 3*x^2)/ (1-x)^3. - Colin Barker, Sep 13 2012
EXAMPLE
a(2) = 30 = sum of row 2 terms of triangle A131873: (15 + 8 + 7).
a(2) = 30 = (1, 2, 1) dot (1, 11, 7) = (1 + 22 + 7).
MAPLE
PROG
(PARI) a(n)=(7*n^2+15*n+2)/2 \\ Charles R Greathouse IV, Jun 16 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Jul 22 2007
EXTENSIONS
More terms from Vladimir Joseph Stephan Orlovsky, Dec 04 2008
STATUS
approved