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Search: id:A080875
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| A080875 |
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a(n)*a(n+3) - a(n+1)*a(n+2) = 5, given a(0)=a(1)=1, a(2)=6. |
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5
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| 1, 1, 6, 11, 71, 131, 846, 1561, 10081, 18601, 120126, 221651, 1431431, 2641211, 17057046, 31472881, 203253121, 375033361, 2421980406, 4468927451, 28860511751, 53252096051, 343904160606, 634556225161, 4097989415521
(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^3 - 6*x^2 + x + 1)/(x^4 - 12*x^2 + 1)
a(n+4)=12*a(n+2)-a(n) [From Richard Choulet (richardchoulet(AT)yahoo.fr), Dec 04 2008]
a(n) = (0.25 + ((sqrt(6 + sqrt(35)) - sqrt(6 - sqrt(35)))/(4*sqrt(35))))*(sqrt(6 + sqrt(35)))^n + (0.25 + ((sqrt(6 + sqrt(35)) - sqrt(6 - sqrt(35)))/(4*sqrt(35))))*(sqrt(6 - sqrt(35)))^n + (0.25 - ((sqrt(6 + sqrt(35)) - sqrt(6 - sqrt(35)))/(4*sqrt(35))))*( - sqrt(6 + sqrt(35)))^n + (0.25 - ((sqrt(6 + sqrt(35)) - sqrt(6 - sqrt(35)))/(4*sqrt(35))))*( - (sqrt(6 - sqrt(35))))^n [From Richard Choulet (richardchoulet(AT)yahoo.fr), Dec 06 2008]
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CROSSREFS
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Cf. A080871, A080872, A080873, A080874.
Bisections are A023038 and A077417.
Sequence in context: A110445 A128387 A061519 this_sequence A001543 A077705 A077697
Adjacent sequences: A080872 A080873 A080874 this_sequence A080876 A080877 A080878
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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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