Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #11 Oct 04 2013 13:15:15
%S 1,5,29,169,869,985,5741,26041,29405,33461,151201,195025,756029,
%T 780361,998789,1136689,5116301,6625109,23384789,26308105,29816641,
%U 33929309,38613965,135777769,225058681,657744361,678888869,700763309,788361985,864683429,890206969,1012771061,1152597605
%N Largest number in an integer 6-tuple (a, b, c, d, e, f) satisfying the Markoff(6) equation a^2+b^2+c^2+d^2+e^2+f^2 = 6*a*b*c*d*e*f.
%C 2*a(n)^2-1 is a square for a(1), a(2), a(3), a(4), a(6), a(7), a(10), a(12), a(16), a(18), a(23), a(25),...
%e 1 is in the sequence since (1, 1, 1, 1, 1, 1) is a solution to a^2+b^2+c^2+d^2+e^2+f^2 = 6*a*b*c*d*e*f. 5, 29, and 169 are in the sequence since (5, 1, 1, 1, 1, 1), (29, 5, 1, 1, 1, 1), (169, 29, 1, 1, 1, 1) are solutions.
%Y Cf. A001653, A229242 (Markoff(5)).
%K nonn
%O 1,2
%A _Shanzhen Gao_, Sep 18 2013