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%I #9 Nov 04 2022 20:11:27
%S 1,1343,2372159,9788425919,5705771236038721,17999572487701067948161,
%T 173658539553825212149513251457,
%U 75727152767742719949099952561135816319,437825148963391521638828389137484882137402791039
%N Positive integers c such that c^2 = a + b and a^2 + b^2 = m^4 for some coprime integers a, b, m.
%C Corresponding values of m are given in A166929 - see it for further details.
%C Terms with positive a, b are given in A167438.
%C This is the absolute value of a bisection of a generalized Somos-5 sequence. - _Michael Somos_, Nov 04 2022
%o (PARI) {a(n) = local(x, v); n = abs(2*n+1); (x = m-> v[abs(m)+1]); v = vector(max(3, n+1), m, 1); v[3] = -3; for(k=3, n, v[k+1] = -(13*x(k-1)*x(k-4) + 42*x(k-2)*x(k-3)) / x(k-5)); abs(x(n))}; /* _Michael Somos_, Nov 04 2022 */
%K nonn
%O 1,2
%A _Max Alekseyev_, Nov 03 2009
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