A227206 - 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, 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

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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),...

LINKS

Table of n, a(n) for n=1..33.

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

Adjacent sequences: A227203 A227204 A227205 * A227207 A227208 A227209

KEYWORD

nonn

AUTHOR

Shanzhen Gao, Sep 18 2013

STATUS

approved