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A115357
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Periodic {1,1,1,0,2,0}.
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2
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1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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COMMENTS
| Diagonal sums of number triangle A115356.
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FORMULA
| G.f. : (1+2x+2x^2)/(1+x-x^3-x^4); a(n)=-a(n-1)+a(n-3)+a(n-4); a(n)=-cos(2*pi*n/3+pi/6)/sqrt(3)+sin(2*pi*n/3+pi/6)/3+(-1)^n/2+5/6.
Sequence shifted right by 2 is additive with a(p^e) = 1 if p = 2 or 3, 0 otherwise.
a(n)=1/18*{-(n mod 6)+7*[(n+1) mod 6]-5*[(n+2) mod 6]+2*[(n+3) mod 6]+[(n+4) mod 6]+[(n+5) mod 6]} - Paolo P. Lava (paoloplava(AT)gmail.com), Nov 21 2006
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CROSSREFS
| Cf. A171182. [From Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Dec 04 2009]
Sequence in context: A050600 A129691 A117454 * A171182 A063962 A084114
Adjacent sequences: A115354 A115355 A115356 * A115358 A115359 A115360
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Jan 21 2006
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