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A028356 Simple periodic sequence underlying clock sequence A028354. 12
1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Contribution from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 15 2010: (Start)

Continued fraction expansion of (28+sqrt(2730))/56.

Decimal expansion of 1112/9009.

Partial sums of 1 followed by A130151.

First differences of A028357. (End)

REFERENCES

Zdenek Horsky, "Prazsky Orloj" ["The Astronomical Clock of Prague", in Czech], Panorama, Prague, 1988, pp. 76-78.

M. Krizek, A. Solcova and L. Somer, Construction of Sindel sequences, Comment. Math. Univ. Carolin., 48 (2007), 373-388.

LINKS

N. J. A. Sloane, My favorite integer sequences, in Sequences and their Applications (Proceedings of SETA '98).

Index to sequences with linear recurrences with constant coefficients, signature (1,0,-1,1).

FORMULA

Sum of any six successive terms is 15.

Coefficients in expansion of (1 + 2x + 3x^2 + 4x^3 + 3x^4 + 2x^5)/(1 - x^6).

a(n)=(1/3)*{[cos(2*n*Pi/3) + 1/2]*[1 + (-1)^n] + 2*[cos(2*(n + 5)*Pi/3) + 1/2]*[1 + (-1)^(n + 5)] + 3*[cos(2*(n + 4)*Pi/3) + 1/2]*[1 + (-1)^(n + 4)] + [4*cos(2*(n + 3)*Pi/3) + 1/2]*[1 + (-1)^(n + 3)] + [3*cos(2*(n + 2)*Pi/3) + 1/2]*[1 + (-1)^(n + 2)] + [2*cos(2*(n + 1)*Pi/3) + 1/2]*[1 + (-1)^(n + 1)]} - Paolo P. Lava (paoloplava(AT)gmail.com), Oct 09 2006

a(n)=1/3*[n mod 6+(n+1) mod 6+(n+2) mod 6] - Paolo P. Lava (paoloplava(AT)gmail.com), Oct 09 2006

MATHEMATICA

CoefficientList[ Series[(1 + 2x + 3x^2 + 4x^3 + 3x^4 + 2x^5)/(1 - x^6), {x, 0, 85}], x]

PROG

(MAGMA) &cat[ [1, 2, 3, 4, 3, 2]: n in [1..20] ]; [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 15 2010]

CROSSREFS

Cf. A000034, A068073, A028354.

Cf. A177924 (decimal expansion of (28+sqrt(2730))/56), A130151 (repeat 1, 1, 1, -1, -1, -1), A028357 (partial sums of A028356). [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 15 2010]

Sequence in context: A008287 A017859 A171456 * A073791 A030340 A122453

Adjacent sequences:  A028353 A028354 A028355 * A028357 A028358 A028359

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

Additional comments from Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 01 2002

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Last modified February 13 19:01 EST 2012. Contains 205535 sequences.