A182585 Markov numbers that are semiprime.

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

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