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A083043 Integers y such that 11x^2-9y^2=2 for some integer x. 5
1, 21, 419, 8359, 166761, 3326861, 66370459, 1324082319, 26415275921, 526981436101, 10513213446099, 209737287485879, 4184232536271481, 83474913437943741, 1665314036222603339, 33222805811014123039 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..15.

Tanya Khovanova, Recursive Sequences

Index entries for two-way infinite sequences

Index entries for linear recurrences with constant coefficients, signature (20,-1)

FORMULA

G.f.: (1+x)/(1-20*x+x^2). a(n)=20*a(n-1)-a(n-2). a(-1-n)=-a(n).

11*A075839(n)^2-9*a(n)^2=2.

a(n+1)=10*a(n)+sqrt(99*a(n)^2+22). - Richard Choulet, Sep 27 2007

MATHEMATICA

LinearRecurrence[{20, -1}, {1, 21}, 30] (* Harvey P. Dale, Jun 02 2014 *)

PROG

(PARI) a(n)=subst(poltchebi(n+1)-poltchebi(n), x, 10)/9

CROSSREFS

Sequence in context: A219308 A020534 A106656 * A162807 A097833 A163145

Adjacent sequences:  A083040 A083041 A083042 * A083044 A083045 A083046

KEYWORD

easy,nonn

AUTHOR

Michael Somos, Apr 17 2003

EXTENSIONS

Corrected by T. D. Noe, Nov 07 2006

STATUS

approved

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Last modified August 17 11:40 EDT 2017. Contains 290635 sequences.