A107652 Triangle of numbers arising in enumeration of binary trees.

1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 4, 8, 10, 8, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 34, 68, 94, 104, 94, 68, 34, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 496, 992, 1420, 1712, 1816, 1712, 1420, 992, 496, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• tabl
• easy

Comments

Essentially the same triangle as in A008301, but with more zeros.

Links

• Christiane Poupard, Deux propriétés des arbres binaires ordonnés stricts, Europ. J. Combin., Vol. 10 (1989), pp. 369-374.

Crossrefs

Cf. A008301. Leading diagonal and row sums = (essentially) A107652.