login

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”).

A227206
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.
1
1, 5, 29, 169, 869, 985, 5741, 26041, 29405, 33461, 151201, 195025, 756029, 780361, 998789, 1136689, 5116301, 6625109, 23384789, 26308105, 29816641, 33929309, 38613965, 135777769, 225058681, 657744361, 678888869, 700763309, 788361985, 864683429, 890206969, 1012771061, 1152597605
OFFSET
1,2
COMMENTS
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),...
EXAMPLE
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.
CROSSREFS
Cf. A001653, A229242 (Markoff(5)).
Sequence in context: A182017 A291017 A141812 * A001653 A370175 A141814
KEYWORD
nonn
AUTHOR
Shanzhen Gao, Sep 18 2013
STATUS
approved