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A010705 Period 2: repeat (3,7). 3
3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3, 7, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Continued fraction expansion of (21 + 5sqrt(21))/14 (decimal expansion is given by A176106). - R. J. Mathar, Mar 08 2012

If an initial 2 is prepended to this sequence, it is Sylvester's sequence (A000058) modulo 10. - Alonso del Arte, Mar 25 2015

LINKS

Table of n, a(n) for n=0..80.

Index entries for linear recurrences with constant coefficients, signature (0,1).

FORMULA

a(n) = -2*(-1)^n + 5 = 7*(n mod 2) + 3*[(n+1) mod 2]. - Paolo P. Lava, Oct 20 2006

G.f. (3+7x)/((1-x)(1+x)). - R. J. Mathar, Nov 21 2011

MATHEMATICA

Table[Mod[30n - 15 + 2(-1)^n, 10], {n, 100}] (* Alonso del Arte, Mar 25 2015 *)

PadRight[{}, 120, {3, 7}] (* Harvey P. Dale, Jan 14 2019 *)

PROG

(PARI) a(n)=3+n%2*4 \\ Charles R Greathouse IV, Dec 21 2011

CROSSREFS

Sequence in context: A021732 A244191 A161973 * A244189 A200481 A016665

Adjacent sequences:  A010702 A010703 A010704 * A010706 A010707 A010708

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified July 21 21:14 EDT 2019. Contains 325199 sequences. (Running on oeis4.)