A114298 First row of Modified Schroeder numbers for q=7 (A114294).

1, 1, 1, 1, 2, 5, 13, 34, 110, 393, 1449, 5390, 21534, 90418, 389265, 1694769, 7593330, 34910142, 163314286, 772044618, 3702870682, 18017064221, 88689351909, 440271808570, 2205020557614, 11141413883818, 56737939027682

Offset

0,5

Comments

a(i) is the number of paths from (0,0) to (i,i) using steps of length (0,1), (1,0) and (1,1), not passing above the line y=x nor below the line y=3x/4.

References

C. Hanusa (2005). A Gessel-Viennot-Type Method for Cycle Systems with Applications to Aztec Pillows. PhD Thesis. University of Washington, Seattle, USA.

Links

Table of n, a(n) for n=0..26.

Example

The number of paths from (0,0) to (5,5) staying between the lines y=x and y=3x/4 using steps of length (0,1), (1,0) and (1,1) is a(5)=5.

Crossrefs

See also A112833-A112844 and A114292-A114299.

Sequence in context: A148289 A148290 A029885 * A112839 A331755 A137674

Adjacent sequences: A114295 A114296 A114297 * A114299 A114300 A114301

Keyword

nonn

Author

Christopher Hanusa (chanusa(AT)math.binghamton.edu), Nov 21 2005

Status

approved