[seqfan] Flat steps in Schroeder paths that are not the first step

[David Scambler]

Two observations,


1)      The number of flat steps that are not the first step in Schroeder n-paths is equal to the total number of steps in Schroeder (n-1)-paths.

A089164<http://oeis.org/A089164> 3, 19, 107, 591, 3259, 18019, 99987



2)      The number of Schroeder n-paths that have exactly one flat step that is not the first step

0,0,3,19,107,591,3259,18019,  matches A046224<http://oeis.org/A046224> for n>=2, where A046224<http://oeis.org/A046224> is the central elements of

the so-called Pascal 1/2-triangle.

Kinda interesting...
dave