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A080875 a(n)*a(n+3) - a(n+1)*a(n+2) = 5, given a(0)=a(1)=1, a(2)=6. 5
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; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..1500

FORMULA

G.f.: (-x^3 - 6*x^2 + x + 1)/(x^4 - 12*x^2 + 1).

a(n+4) = 12*a(n+2)-a(n). [Richard Choulet, Dec 04 2008]

a(n) = (1/4 + ((sqrt(6 + sqrt(35)) - sqrt(6 - sqrt(35)))/(4*sqrt(35))))*(sqrt(6 + sqrt(35)))^n + (1/4 + ((sqrt(6 + sqrt(35)) - sqrt(6 - sqrt(35)))/(4*sqrt(35))))*(sqrt(6 - sqrt(35)))^n + (1/4 - ((sqrt(6 + sqrt(35)) - sqrt(6 - sqrt(35)))/(4*sqrt(35))))*( - sqrt(6 + sqrt(35)))^n + (1/4 - ((sqrt(6 + sqrt(35)) - sqrt(6 - sqrt(35)))/(4*sqrt(35))))*( - (sqrt(6 - sqrt(35))))^n. [Richard Choulet, Dec 06 2008]

CROSSREFS

Cf. A080871, A080872, A080873, A080874.

Bisections are A023038 and A077417.

Sequence in context: A128387 A061519 A193664 * A001543 A077705 A077697

Adjacent sequences:  A080872 A080873 A080874 * A080876 A080877 A080878

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Feb 22 2003

STATUS

approved

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Last modified August 17 11:51 EDT 2019. Contains 326057 sequences. (Running on oeis4.)