A084536 Triangular array related to Motzkin triangle A026300.

1, 1, 3, 1, 6, 10, 1, 9, 29, 36, 1, 12, 57, 132, 137, 1, 15, 94, 315, 590, 543, 1, 18, 140, 612, 1629, 2628, 2219, 1, 21, 195, 1050, 3605, 8127, 11732, 9285, 1, 24, 259, 1656, 6950, 19992, 39718, 52608, 39587, 1, 27, 332, 2457, 12177, 42498, 106644, 191754

Offset

0,3

Comments

Reversal of A091965. Row sums give A026378. - Philippe Deléham, Mar 23 2007

References

A. Nkwanta, Lattice paths and RNA secondary structures, in African Americans in Mathematics, ed. N. Dean, Amer. Math. Soc., 1997, pp. 137-147.

Links

Table of n, a(n) for n=0..52.

Formula

T(n,n) = A002212(n+1). - Philippe Deléham, Mar 23 2007

Example

Triangle begins
  1;
  1,   3;
  1,   6,  10;
  1,   9,  29,  36;
  1,  12,  57, 132, 137; ...

Crossrefs

Sequence in context: A163213 A095066 A169955 * A110770 A106855 A064282

Adjacent sequences: A084533 A084534 A084535 * A084537 A084538 A084539

Keyword

nonn,tabl

Author

N. J. A. Sloane, Jun 29 2003

Extensions

More terms from Philippe Deléham, Mar 23 2007

Status

approved