OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
a(n) = (6 + 115*n - 150*n^2 + 125*n^3)/6.
G.f.: (1+4*x)^3/(1-x)^4.
From Elmo R. Oliveira, Jun 06 2025: (Start)
E.g.f.: exp(x)*(6 + 90*x + 225*x^2 + 125*x^3)/6.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). (End)
MATHEMATICA
CoefficientList[Series[(1 + 4 x)^3 / (1 - x)^4, {x, 0, 40}], x] (* Vincenzo Librandi, Aug 09 2013 *)
PROG
(Magma) [(6+115*n-150*n^2+125*n^3)/6: n in [0..40]]; // Vincenzo Librandi, Aug 09 2013
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Mar 23 2003
STATUS
approved
