The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A333689 Number of self-avoiding paths in (2*n+1) X 5 grid starting the upper left corner, passing through the center of grid and finishing the lower right corner. 2
 1, 101, 7056, 610765, 53968755, 4775133828, 422813081886, 37441305792927, 3315577406171322, 293609559097456363, 26000534802119070508, 2302473191851860468948, 203895143590466986654399, 18055900558029962460378646, 1598937211532791928425001493, 141593611215040047912334138664 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Seiichi Manyama, Table of n, a(n) for n = 0..500 PROG (Python) # Using graphillion from graphillion import GraphSet import graphillion.tutorial as tl def A333685(n, k): if n == 0 or k == 0: return 1 universe = tl.grid(2 * n, 2 * k) GraphSet.set_universe(universe) start, goal = 1, (2 * n + 1) * (2 * k + 1) paths = GraphSet.paths(start, goal).including((start + goal) // 2) return paths.len() def A333689(n): return A333685(n, 2) print([A333689(n) for n in range(15)]) CROSSREFS Column 2 of A333685. Sequence in context: A167626 A017764 A217677 * A291990 A303572 A152756 Adjacent sequences: A333686 A333687 A333688 * A333690 A333691 A333692 KEYWORD nonn AUTHOR Seiichi Manyama, Apr 02 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 12 16:34 EDT 2024. Contains 373334 sequences. (Running on oeis4.)