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A096230
Period 5: repeat [9, 7, 5, 3, 1].
1
9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1, 9, 7, 5, 3, 1
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
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
Sequence in context: A191760 A237841 A109846 * A114433 A222129 A188141
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