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A010883 Simple periodic sequence: repeat 1,2,3,4. 7
1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Partial sums are given by A130482(n)+n+1. - Hieronymus Fischer, Jun 08 2007

1234/9999=0,123412341234... - Eric Desbiaux, Nov 03 2008

Terms of the simple continued fraction of 5/(2*sqrt(39)-9). - Paolo P. Lava, Feb 16 2009

LINKS

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

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

FORMULA

a(n) = 1 + (n mod 4) - Paolo P. Lava, Nov 21 2006

a(n)=A010873(n)+1. Also a(n)=1/2*(5-(-1)^n-2*(-1)^((2n-1+(-1)^n)/4))). G.f.: g(x)=(4x^3+3x^2+2x+1)/(1-x^4)=(4x^5-5x^4+1)/((1-x^4)(1-x)^2). - Hieronymus Fischer, Jun 08 2007

a(n) = (7*(n mod 4)+(n+1 mod 4)+(n+2 mod 4)+(n+3 mod 4))/6 (cf. forms of modular arithmetic of Paolo P. Lava, i.e. see A146094). - Bruno Berselli, Sep 27 2010

a(n) = 5/2 -cos(Pi*n/2) -sin(Pi*n/2) -(-1)^n/2.- R. J. Mathar, Oct 08 2011

MATHEMATICA

PadRight[{}, 120, {1, 2, 3, 4}] (* Harvey P. Dale, Aug 02 2016 *)

PROG

(PARI) a(n)=(n-1)%4+1 \\ Charles R Greathouse IV, Jun 11 2015

CROSSREFS

Cf. A010872, A010873, A010874, A010875, A010876, A004526, A002264, A002265, A002266.

Cf. A177037 (decimal expansion of (9+2*sqrt(39))/15). - Klaus Brockhaus, May 01 2010

Sequence in context: A171171 A159957 A053840 * A011542 A260688 A053344

Adjacent sequences:  A010880 A010881 A010882 * A010884 A010885 A010886

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified November 18 02:54 EST 2017. Contains 294840 sequences.