OFFSET
0,1
COMMENTS
From Jaume Oliver Lafont, May 30 2010: (Start)
3 divides a(n).
Sum_{k>=0} 1/a(k) = Pi/(96*(2+sqrt(2))) = 0.0095849081719... [Jolley eq. 243] (End)
REFERENCES
Jolley, Summation of Series, Dover (1961).
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).
FORMULA
G.f.: -3*(35+6260*x+20178*x^2+6260*x^3+35*x^4)/(x-1)^5. [Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009]
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n > 4. - Wesley Ivan Hurt, Jan 02 2017
MAPLE
A001546:=n->(8*n+1)*(8*n+3)*(8*n+5)*(8*n+7): seq(A001546(n), n=0..50); # Wesley Ivan Hurt, Jan 02 2017
MATHEMATICA
Table[Times@@(8n + {1, 3, 5, 7}), {n, 0, 30}] (* Harvey P. Dale, Jan 09 2011 *)
PROG
(PARI) a(n)=(8*n+1)*(8*n+3)*(8*n+5)*(8*n+7) \\ Charles R Greathouse IV, Oct 03 2011
(Magma) [(8*n+1)*(8*n+3)*(8*n+5)*(8*n+7): n in [0..20]]; // Vincenzo Librandi, Oct 04 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved