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%I #9 Feb 14 2015 23:50:48
%S 3,7,5,11,7,15,13,9,17,23,13,11,27,19,17,25,23,35,19,17,25,39,23,31,
%T 21,19,25,41,33,19,29,51,37,27,49,55,41,31,47,29,23,37,45,35,51,43,63,
%U 31,25,67
%N Fundamental positive solution y = y2(n) of the second class of the Pell equation x^2 - 2*y^2 = A007522(n), n>=1 (primes congruent to 7 mod 8).
%C The corresponding fundamental solution x2(n) of this second class of positive solutions is given in A254766(n).
%C See the comments and the Nagell reference in A254764.
%F A254766(n)^2 - 2*a(n)^2 = A007522(n) gives the second smallest positive (proper) solution of this (generalized) Pell equation.
%F a(n) = 2*A254764(n) - 3*A254765(n), n >= 1.
%e n = 2: 11^2 - 2*7^2 = 121 - 98 = 23.
%e The smallest positive solution is (x1(2), y1(2)) = (5, 1) from (A254764(2), A254765(2)).
%e See also A254766.
%e a(4) = 2*7 - 3*1 = 11.
%Y Cf. A007522, A254766, A254764,A254765, A254760, A254761, A254762, A254763.
%K nonn,easy
%O 1,1
%A _Wolfdieter Lang_, Feb 11 2015
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