A178042 Consider the weighted Farey tree A177405/A177407; a(n) = row at which the denominator 2n+1 first appears (assumes first row is labeled row 1).

1, 2, 3, 3, 3, 4, 4, 5, 4, 4, 5, 5, 5, 4, 5, 5, 6, 6, 6, 6, 5, 5, 6, 5, 6, 7, 5, 5, 7, 6, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 6, 7, 8, 7, 7, 7, 7, 7, 6, 7, 6, 7, 7, 7, 7, 6, 7, 8, 7, 7, 7, 7, 7, 7, 7, 6, 7, 6, 8, 8, 7, 7, 8, 8, 7, 8, 7, 7, 7, 6, 6, 8, 7, 7, 7, 8, 8, 8, 7, 7, 7, 8, 8, 7, 8, 8, 8, 7, 8, 8

Offset

0,2

Comments

Equals A177903 + 1. See that entry for further information.

Links

Table of n, a(n) for n=0..100.

Crossrefs

Sequence in context: A334220 A234016 A029119 * A308950 A193832 A293137

Adjacent sequences: A178039 A178040 A178041 * A178043 A178044 A178045

Keyword

nonn

Author

N. J. A. Sloane, Dec 16 2010

Status

approved