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A077244 Bisection (odd part) of Chebyshev sequence with Diophantine property. 4
3, 22, 173, 1362, 10723, 84422, 664653, 5232802, 41197763, 324349302, 2553596653, 20104423922, 158281794723, 1246149933862, 9810917676173, 77241191475522, 608118614128003, 4787707721548502, 37693543158260013 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

3*a(n)^2 - 5*b(n)^2 = 7, with the companion sequence b(n)= A077243(n).

The even part is A077246(n) with Diophantine companion A077245(n).

LINKS

Index entries for sequences related to linear recurrences with constant coefficients

Tanya Khovanova, Recursive Sequences

Index entries for sequences related to Chebyshev polynomials.

FORMULA

a(n)= (2*T(n+1, 4)+T(n, 4))/3, with T(n, x) Chebyshev's polynomials of the first kind, A053120. T(n, 4)= A001091(n).

G.f.: (3-2*x)/(1-8*x+x^2).

EXAMPLE

22 = a(1) = sqrt((5*A077243(1)^2 + 7)/3) = sqrt((5*17^2 + 7)/3) = sqrt(484) = 22.

CROSSREFS

Sequence in context: A192365 A074578 A074576 * A138899 A132595 A065204

Adjacent sequences:  A077241 A077242 A077243 * A077245 A077246 A077247

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Nov 08 2002

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Last modified February 17 08:44 EST 2012. Contains 205998 sequences.