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Search: id:A117444
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| A117444 |
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Periodic {0,1,2,-2,-1}. |
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+0
3
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| 0, 1, 2, -2, -1, 0, 1, 2, -2, -1, 0, 1, 2, -2, -1, 0, 1, 2, -2, -1, 0, 1, 2, -2, -1, 0, 1, 2, -2, -1, 0, 1, 2, -2, -1, 0, 1, 2, -2, -1, 0, 1, 2, -2, -1
(list; graph; listen)
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OFFSET
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0,3
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FORMULA
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G.f.: x(1+3x+x^2)/(1+x+x^2+x^3+x^4)=x(1+2x^2-2x^3-x^4)/(1-x^5); a(n)=sum{k=0..5, L(k(k^2-n)/5)}/2, where L(j/p) is the Legendre symbol of j and p; a(n)=sqrt(2+2/sqrt(5))*sin(2*pi*n/5)-sqrt(2-2/sqrt(5))*sin(4*pi*n/5).
a(n)=-(1/5)*{(n mod 5)+[(n+1) mod 5]-4*[(n+2) mod 5]+[(n+3) mod 5]+[(n+4) mod 5]}, with n>=0 - Paolo P. Lava (ppl(AT)spl.at), Jun 11 2007
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CROSSREFS
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Sequence in context: A108423 A092339 A079693 this_sequence A015504 A055892 A104244
Adjacent sequences: A117441 A117442 A117443 this_sequence A117445 A117446 A117447
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KEYWORD
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easy,sign
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AUTHOR
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Paul Barry (pbarry(AT)wit.ie), Mar 16 2006
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