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 (5,-10,10,-5,1).
FORMULA
G.f.: 24*( x^4 + 121*x^3 + 381*x^2 + 121*x + 1 )/( 1-x )^5. - Maksym Voznyy (voznyy(AT)mail.ru), Jul 26 2009 [corrected by Jaume Oliver Lafont, Sep 19 2009]
From Amiram Eldar, Sep 20 2022: (Start)
Sum_{n>=0} 1/a(n) = sqrt(10-22/sqrt(5))*Pi/30.
Sum_{n>=0} (-1)^n/a(n) = 4*log(2)/15 - 2*log(phi)/(3*sqrt(5)), where phi is the golden ratio (A001622). (End)
MATHEMATICA
Table[Times@@(5n+{1, 2, 3, 4}), {n, 0, 30}] (* Harvey P. Dale, Jul 15 2019 *)
PROG
(Magma) [(5*n+1)*(5*n+2)*(5*n+3)*(5*n+4): n in[0..50]] // Vincenzo Librandi, Aug 02 2010
(PARI) a(n)=(5*n+1)*(5*n+2)*(5*n+3)*(5*n+4) \\ Charles R Greathouse IV, Oct 21 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved