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Search: id:A058232
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| A058232 |
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a(n)=(a(n-1)a(n-5)+a(n-2)a(n-4)+a(n-3)^2)/a(n-6). |
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+0
1
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| 0, 1, 0, 1, 1, -1, -1, 0, 0, 1, -1, -1, -1, -2, 1, 2, -1, 2, 1, -3, -3, -1, -4, 4, 1, -3, -5, -9, 8, 15, -4, 17, -8, -23, -3, -21, -49, 52, 76, -47, 11, -133, 79, 238, 97, 518, -417, -750, 625, -647, -343, 1967, 3048, -1000, 5553, -8375, -4233, 13375, 10912, 33503
(list; graph; listen)
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OFFSET
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0,14
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REFERENCES
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N. D. Elkies (elkies(AT)math.harvard.edu), email, Nov 29, 2000.
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LINKS
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T. D. Noe, Table of n, a(n) for n=0..300
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FORMULA
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a(-n)=-a(n). a(n+6)*a(n-6)=a(n+4)*a(n-4)+a(n+2)*a(n-2).
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PROGRAM
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(PARI) a(n)=local(an, a0, num); if(n<0, -a(-n), if(n==0, 0, a0=[1, 0, 1, 1, -1, -1, 0, 0, 1, -1, -1, -1, -2, 1]; an=vector(n); for(k=1, n, an[k]=if(k<15, a0[k], (num=an[k-1]*an[k-5]+an[k-2]*an[k-4]+an[k-3]^2)/an[k-6])); an[n]))
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CROSSREFS
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Cf. A006722.
Sequence in context: A053275 A025816 A025813 this_sequence A116933 A088433 A050334
Adjacent sequences: A058229 A058230 A058231 this_sequence A058233 A058234 A058235
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KEYWORD
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sign,easy,nice
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AUTHOR
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Michael Somos
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