OFFSET
0,1
LINKS
T. D. Noe, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
G.f.: 6*(1 + 52*x + 68*x^2 + 4*x^3)/(1 - x)^4. - Stefano Spezia, Jan 03 2023
Sum_{n>=0} 1/a(n) = sqrt(2*(25-11*sqrt(5))/5)*Pi/20 + log(phi)/(2*sqrt(5)), where phi is the golden ratio (A001622). - Amiram Eldar, Jan 26 2023
From Elmo R. Oliveira, Sep 07 2025: (Start)
E.g.f.: exp(x)*(6 + 330*x + 525*x^2 + 125*x^3).
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). (End)
MAPLE
MATHEMATICA
Table[(5*n + 1)*(5*n + 2)*(5*n + 3), {n, 0, 100}] (* Harvey P. Dale, Apr 21 2011 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 11 1996
STATUS
approved