A132278 Number of distinct terms in rows 1 through n of the triangle of the Narayana numbers (A001263).

1, 1, 2, 3, 5, 7, 10, 13, 17, 21, 26, 31, 37, 43, 49, 56, 64, 72, 81, 90, 100, 110, 121, 132, 144, 156, 169, 182, 196, 210, 225, 240, 256, 272, 289, 306, 324, 342, 361, 380, 400, 420, 441, 462, 484, 506, 529, 552, 575, 599, 624, 649, 675, 701, 728, 755, 783

Offset

1,3

Links

Table of n, a(n) for n=1..57.

Example

a(6)=7 because there are 7 distinct terms in the rows 1 through 6 of the triangle of the Narayana numbers: 1; 1,1; 1,3,1; 1,6,6,1; 1,10,20,10,1; 1,15,50,50,15,1.

Maple

seq(nops(`union`(seq({seq(binomial(n, k)*binomial(n, k-1)/n, k=1..n)}, n=1..m))), m=1..57);

Crossrefs

Cf. A001263.

Sequence in context: A022335 A022780 A075353 * A025700 A033638 A194205

Adjacent sequences: A132275 A132276 A132277 * A132279 A132280 A132281

Keyword

nonn

Author

Emeric Deutsch, Aug 26 2007

Status

approved