OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,-1,1). - R. J. Mathar, Apr 20 2010
FORMULA
From R. J. Mathar, Apr 20 2010: (Start)
a(n) = a(n-1) - a(n-6) + a(n-7).
G..f: ( -1-6*x-16*x^2+18*x^3-4*x^4-2*x^5-15*x^6 ) / ( (x-1)*(x^2+1)*(x^4-x^2+1) ). (End)
a(n) = a(n-12). - G. C. Greubel, Mar 20 2016
MATHEMATICA
PowerMod[7, Range[0, 80], 26] (* or *) LinearRecurrence[{1, 0, 0, 0, 0, -1, 1}, {1, 7, 23, 5, 9, 11, 25}, 81] (* Harvey P. Dale, Dec 26 2011 *)
PROG
(Sage) [power_mod(7, n, 26)for n in range(0, 81)] # Zerinvary Lajos, Nov 27 2009
(PARI) a(n) = lift(Mod(7, 26)^n); \\ Altug Alkan, Mar 20 2016
(Magma) [Modexp(7, n, 26): n in [0..100]]; // Bruno Berselli, Mar 22 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 12 2002
STATUS
approved