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A156536 Period length 12: repeat 7,5,-1,1,-5,-7,-7,-5,1,-1,5,7. 0
7, 5, -1, 1, -5, -7, -7, -5, 1, -1, 5, 7, 7, 5, -1, 1, -5, -7, -7, -5, 1, -1, 5, 7, 7, 5, -1, 1, -5, -7, -7, -5, 1, -1, 5, 7, 7, 5, -1, 1, -5, -7, -7, -5, 1, -1, 5, 7, 7, 5, -1, 1, -5, -7, -7, -5, 1, -1, 5, 7, 7, 5, -1, 1, -5, -7, -7, -5, 1, -1, 5, 7, 7, 5, -1, 1, -5, -7, -7, -5, 1, -1, 5, 7, 7, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..85.

FORMULA

a(n) = A154811(n+6)-A154811(n).

a(n)=(1/6)*{-[(n+1) mod 12]-3*[(n+2) mod 12]+[(n+3) mod 12]-3*[(n+4) mod 12]-[(n+5) mod 12]+[(n+7) mod 12]+3*[(n+8) mod 12]-[(n+9) mod 12]+3*[(n+10) mod 12]+[(n+11) mod 12]}, with n>=0 [From Paolo P. Lava, Feb 13 2009]

a(n)= -a(n-6). G.f.: -(x-1)*(7*x^4+12*x^3+11*x^2+12*x+7)/((1+x^2)*(x^4-x^2+1)). - R. J. Mathar, Apr 10 2009

CROSSREFS

Cf. A154870.

Sequence in context: A241837 A145176 A093205 * A110191 A233090 A254177

Adjacent sequences:  A156533 A156534 A156535 * A156537 A156538 A156539

KEYWORD

sign,easy

AUTHOR

Paul Curtz, Feb 09 2009

EXTENSIONS

Edited by R. J. Mathar, Apr 10 2009

STATUS

approved

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Last modified July 20 14:46 EDT 2017. Contains 289625 sequences.