OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,-1,1).
FORMULA
a(n) = 8^n mod 10. [Zerinvary Lajos, Nov 27 2009]
G.f.: -(7*x - 3*x^2 + 5*x^3 + 1)/ ((x - 1)*(1 + x^2)). [R. J. Mathar, Apr 20 2010]
a(n) = +a(n-1) -a(n-2) +a(n-3). [R. J. Mathar, Apr 20 2010]
MATHEMATICA
Table[PowerMod[8, n, 10], {n, 0, 200}] (* Vladimir Joseph Stephan Orlovsky, Jun 10 2011 *)
LinearRecurrence[{1, -1, 1}, {1, 8, 4, 2}, 100] (* Harvey P. Dale, Jul 01 2019 *)
PROG
(Sage) [power_mod(8, n, 10)for n in range(0, 105)] # Zerinvary Lajos, Nov 27 2009
(PARI) a(n)=lift(Mod(8, 10)^n) \\ Charles R Greathouse IV, Dec 29 2012
(Magma) [Modexp(8, n, 10): n in [0..100]]; // Vincenzo Librandi, Jun 30 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved