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A080880 a(n)*a(n+3) - a(n+1)*a(n+2) = 2^n, given a(0)=1, a(1)=2, a(2)=2. 6
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; refs; listen; history; internal format)
OFFSET

0,2

FORMULA

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]

CROSSREFS

Cf. A080876, A080877, A080878, A080879, A080881, A080882.

Sequence in context: A034420 A028410 A050216 * A120843 A205674 A021447

Adjacent sequences:  A080877 A080878 A080879 * A080881 A080882 A080883

KEYWORD

nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Feb 22 2003

EXTENSIONS

More terms from Ralf Stephan (ralf(AT)ark.in-berlin.de), Jul 25 2003

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Last modified February 16 14:37 EST 2012. Contains 205930 sequences.