OFFSET
1,1
COMMENTS
Decimal expansion of 9 + 1/2 + 1/4 + 1/313 + 1/378244 + 1/2959729702407 = 975310/99999. - Bruno Berselli, Oct 02 2018
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,1).
FORMULA
a(n) = 1 + 2*(-n mod 5). [From Wilson Mathematica program (2004)]
a(n) = 9 - (2*(n-1) mod 10). [From Greathouse PARI program (2014)]
From Robert Israel, Jul 16 2015: (Start)
G.f.: (9 + 7*x + 5*x^2 + 3*x^3 + x^4)/(1 - x^5).
a(n) = a(n-5).
a(n) + a((a(n)+1)/2) = 10. (End)
MAPLE
map(op, [[9, 7, 5, 3, 1]$20]); # Robert Israel, Jul 16 2015
MATHEMATICA
Table[2 Mod[-n, 5] + 1, {n, 105}] (* Robert G. Wilson v, Jul 31 2004 *)
PadRight[{}, 120, {9, 7, 5, 3, 1}] (* Harvey P. Dale, Dec 19 2012 *)
PROG
(PARI) a(n) = 9 - 2*(n-1)%10; \\ Charles R Greathouse IV, Aug 25 2014
(Magma) &cat [[9, 7, 5, 3, 1]: n in [0..20]]; // Vincenzo Librandi, Jul 16 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Odimar Fabeny, Jul 29 2004
EXTENSIONS
Edited by N. J. A. Sloane and Robert G. Wilson v, Jul 31 2004
STATUS
approved