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A219165 Recurrence equation a(n+1) = a(n)^4 - 4*a(n)^2 + 2 with a(0) = 6. 3
6, 1154, 1773462177794, 9892082352510403757550172975146702122837936996354 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Bisection of A003423.

LINKS

Table of n, a(n) for n=0..3.

FORMULA

Let alpha = 3 + 2*sqrt(2). Then a(n) = (alpha)^(4^n) + (1/alpha)^(4^n).

a(n) = A003423(2*n) = A003499(4^n).

Product {n = 0..inf} ((1 + 2/a(n))/(1 - 2/a(n)^2)) = sqrt(2).

CROSSREFS

Cf. A001999, A003423, A003499, A219162, A219163, A219164.

Sequence in context: A268043 A190351 A267071 * A185537 A113159 A159717

Adjacent sequences:  A219162 A219163 A219164 * A219166 A219167 A219168

KEYWORD

nonn,easy

AUTHOR

Peter Bala, Nov 13 2012

STATUS

approved

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Last modified November 18 04:44 EST 2019. Contains 329248 sequences. (Running on oeis4.)