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 A154681: a(n) = Sum_{m=1..n} (2*m*n + m + n + 3).
From Vincenzo Librandi, Mar 05 2012: (Start)
G.f.: x*(7 - 3*x + 2*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}, {7, 25, 60, 118}, 50] (* or *) CoefficientList[Series[(7-3*x+2*x^2)/(1-x)^4, {x, 0, 40}], x] (* Vincenzo Librandi, Mar 05 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jun 29 2009
EXTENSIONS
New name from Vincenzo Librandi, Mar 05 2012
STATUS
approved