OFFSET
7,2
REFERENCES
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 7..1000
R. P. Loh, A. G. Shannon, A. F. Horadam, Divisibility Criteria and Sequence Generators Associated with Fermat Coefficients, Preprint, 1980.
P. A. Piza, Fermat coefficients, Math. Mag., 27 (1954), 141-146.
Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1,1,-6,15,-20,15,-6,1).
FORMULA
a(n) = A258708(n,n-7). - Reinhard Zumkeller, Jun 23 2015
G.f.: x^7*(1 + 6*x + 9*x^2 + 9*x^3 + 10*x^4 + 7*x^5 + 12*x^6 + 6*x^7 + 4*x^8) / ((1 - x)^7*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). - Colin Barker, Mar 28 2017
MAPLE
a := n->floor((2*n)*(2*n+1)*(2*n+2)*(2*n+3)*(2*n+4)*(2*n+5)/7!);
MATHEMATICA
Table[Floor[((2*n)*(2*n+1)*(2*n+2)*(2*n+3)*(2*n+4)*(2*n+5)/7!)], {n, 1, 30}] (* Vincenzo Librandi, Apr 10 2012 *)
With[{c=7!, t=Times@@(2n+Range[0, 5])}, Table[Floor[t/c], {n, 30}]] (* Harvey P. Dale, Apr 20 2014 *)
PROG
[Floor((2*n)*(2*n+1)*(2*n+2)*(2*n+3)*(2*n+4)*(2*n+5)/Factorial(7)): n in [1..30]]; // Vincenzo Librandi, Apr 10 2012
(Haskell)
a000972 n = a258708 n (n - 7) -- Reinhard Zumkeller, Jun 23 2015
(PARI) Vec(x^7*(1 + 6*x + 9*x^2 + 9*x^3 + 10*x^4 + 7*x^5 + 12*x^6 + 6*x^7 + 4*x^8) / ((1 - x)^7*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)) + O(x^50)) \\ Colin Barker, Mar 28 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved