OFFSET
1,1
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
Row sums from A155551: a(n) = Sum_{m=1..n} (2*m*n + m + n - 9).
From Vincenzo Librandi, Mar 04 2012: (Start)
G.f.: x*(-5 + 21*x - 10*x^2)/(1-x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). (End)
MATHEMATICA
CoefficientList[Series[(-5+21*x-10*x^2)/(1-x)^4, {x, 0, 40}], x] (* or *) LinearRecurrence[{4, -6, 4, -1}, {-5, 1, 24, 70}, 50] (* Vincenzo Librandi, Mar 04 2012 *)
Table[(2n^3+5n^2-17n)/2, {n, 40}] (* Harvey P. Dale, May 10 2021 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Vincenzo Librandi, Jun 29 2009
EXTENSIONS
New name from Vincenzo Librandi, Mar 04 2012
STATUS
approved