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Search: id:A080880
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| A080880 |
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a(n)*a(n+3) - a(n+1)*a(n+2) = 2^n, given a(0)=1, a(1)=2, a(2)=2. |
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7
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| 1, 2, 2, 5, 6, 17, 22, 65, 86, 257, 342, 1025, 1366, 4097, 5462, 16385, 21846, 65537, 87382, 262145, 349526, 1048577, 1398102, 4194305, 5592406, 16777217, 22369622, 67108865, 89478486, 268435457, 357913942, 1073741825, 1431655766, 4294967297
(list; graph; listen)
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OFFSET
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0,2
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FORMULA
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a(2n)=(4^n+2)/3, a(2n+1)=4^n+1.
G.f.: (-5*x^3 - 3*x^2 + 2*x + 1)/(4*x^4 - 5*x^2 + 1)
a(n) = 5/6 + 5/12*2^n - 1/6*( - 1)^n - 1/12*( - 2)^n [From Richard Choulet (richardchoulet(AT)yahoo.fr), Dec 07 2008]
a(n + 4) = 5*a(n + 2) - 4*a(n) [From Richard Choulet (richardchoulet(AT)yahoo.fr), Dec 06 2008]
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CROSSREFS
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Cf. A080876, A080877, A080878, A080879, A080881, A080882.
Sequence in context: A034420 A028410 A140870 this_sequence A120843 A021447 A136536
Adjacent sequences: A080877 A080878 A080879 this_sequence A080881 A080882 A080883
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Feb 22 2003
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EXTENSIONS
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More terms from Ralf Stephan (ralf(AT)ark.in-berlin.de), Jul 25 2003
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