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A182585 Markov numbers that are semiprime. 0
34, 169, 194, 985, 4181, 9077, 14701, 51641, 135137, 294685, 499393, 646018, 925765, 1136689, 1346269, 2012674, 6625109, 8399329, 9647009, 11485154, 16964653, 21531778, 43484701, 48928105, 111242465, 137295677, 144059117, 165580141, 225058681, 253191266 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This is to A178444 as semiprimes A001358 are to primes A000040.

LINKS

Table of n, a(n) for n=1..30.

FORMULA

A001358 Intersection A002559. {x, y, or z satisfying x^2 + y^2 + z^2 = 3xyz, also such that A001222(of that number) = 2}.

EXAMPLE

194 is in this sequence because it is a Markoff (or Markov) number, and 194 = 2 * 97.

CROSSREFS

Cf. A001358, A002559, A178444.

Sequence in context: A212407 A190607 A256395 * A191593 A259944 A063652

Adjacent sequences: A182582 A182583 A182584 * A182586 A182587 A182588

KEYWORD

nonn,easy

AUTHOR

Jonathan Vos Post, May 06 2012

STATUS

approved

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Last modified December 4 02:16 EST 2022. Contains 358544 sequences. (Running on oeis4.)