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%I #10 Nov 01 2014 20:46:47
%S 0,8,48,720,43968,910810592,11237392872,373293007784992,
%T 2163097181518680,25456855919300952,11435623194218822640,
%U 869331647875436971195778433312,28252119676370239260178565366349744,1204809438495318797522597458986895824,53363286980501252895913793418543990281912
%N Values of a in A216515.
%F a(n)^2 + 7*A249518(n)^2 = 2^A216515(n)-1.
%Y Cf. A216515, A249518.
%K nonn
%O 1,2
%A _Zak Seidov_, Oct 31 2014