The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A338963 Number of (undirected) paths in C_n X P_n. 5
 1209, 103184, 21272810, 11481159930 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,1 COMMENTS a(8) = 70244258770074672. LINKS Table of n, a(n) for n=3..6. PROG (Python) # Using graphillion from graphillion import GraphSet def make_CnXPk(n, k): grids = [] for i in range(1, k + 1): for j in range(1, n): grids.append((i + (j - 1) * k, i + j * k)) grids.append((i + (n - 1) * k, i)) for i in range(1, k * n, k): for j in range(1, k): grids.append((i + j - 1, i + j)) return grids def A(start, goal, n, k): universe = make_CnXPk(n, k) GraphSet.set_universe(universe) paths = GraphSet.paths(start, goal) return paths.len() def A338963(n): m = n * n s = 0 for i in range(1, m): for j in range(i + 1, m + 1): s += A(i, j, n, n) return s print([A338963(n) for n in range(3, 7)]) CROSSREFS Cf. A268894, A338709, A338960, A338961, A338962. Sequence in context: A279983 A187862 A186864 * A135239 A046043 A358538 Adjacent sequences: A338960 A338961 A338962 * A338964 A338965 A338966 KEYWORD nonn,more AUTHOR Seiichi Manyama, Dec 18 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 July 15 10:24 EDT 2024. Contains 374332 sequences. (Running on oeis4.)