51641
domain: N
Appears in sequences
- Markoff (or Markov) numbers: union of positive integers x, y, z satisfying x^2 + y^2 + z^2 = 3*x*y*z.at n=27A002559
- Sums of groups in A075639.at n=24A075640
- Brilliant numbers k such that 2k+1 is also brilliant.at n=37A085649
- Non-Fibonacci Markoff numbers.at n=15A111032
- Number of imprimitive (periodic) n-bead necklaces with beads of 2 colors when turning over is allowed.at n=42A115119
- Markov numbers that are semiprime.at n=7A182585
- Composite Markoff numbers.at n=12A256395
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 865", based on the 5-celled von Neumann neighborhood.at n=35A273701
- Second member m_2(n) of the Markoff triple MT(n) with largest member m(n) = A002559(n), and smallest member m_1(n) = A305313(n), for n >= 1. These triples are conjectured to be unique.at n=45A305314
- Irregular triangle read by rows: Maximal numbers of the Markoff triples at level L of the Markoff tree, with members of the triples ordered increasingly.at n=30A327345
- Alternative version of the Markov tree A327345.at n=18A368546
- The odd Markoff numbers.at n=20A388291