624132

Appears in sequences

• Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1), U=(1,2), or d=(1,-1) and having abscissa of first return equal to 3k.at n=28A108439
• Number of alternating separable permutations.at n=14A121703
• Expansion of (1/x) * Series_Reversion( x / (1+x+x^4/(1+x)^2) ).at n=23A369581