OFFSET
1,1
COMMENTS
Row sums from A154680.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
From Vincenzo Librandi, Mar 04 2012: (Start)
G.f.: x*(2 + 7*x - 3*x^2)/(1-x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). (End)
MATHEMATICA
LinearRecurrence[{4, -6, 4, -1}, {2, 15, 45, 98}, 50] (* or *) CoefficientList[Series[(2+7*x-3*x^2)/(1-x)^4, {x, 0, 39}], x] (* Vincenzo Librandi, Mar 04 2012 *)
PROG
(PARI) n*(5*n-3)/2+n^3 \\ Charles R Greathouse IV, Jan 11 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jun 29 2009
STATUS
approved