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 A333438 Number of self-avoiding walks of any length from NW corner to its adjacent points on an n X n grid or lattice. 3
 4, 16, 196, 8224, 1064540, 424745876, 527417814424, 2026136052712752 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 COMMENTS From Seiichi Manyama, Apr 07 2020: (Start) a(11) = 864203211903812503254788. a(13) = 32299777937527326896385272155961508. (End) LINKS EXAMPLE a(2) = 4;    S--E   S  E           |  |           *--*    S      S--*    |         |    E      E--* a(3) = 16;    S--E      S  E      S  E--*   S  E--*              |  |      |     |   |     |              *--*      *--*--*   *     *                                  |     |                                  *--*--*    S  E      S  E--*   S  E--*   S  E    |  |      |     |   |     |   |  |    *  *      *  *--*   *--*  *   *  *--*    |  |      |  |         |  |   |     |    *--*      *--*         *--*   *--*--*    S         S--*      S--*      S--*--*    |            |         |            |    E         E--*      E  *      E     *                        |  |      |     |                        *--*      *--*--*    S--*--*   S--*--*   S--*      S--*--*          |         |      |            |    E--*--*   E  *--*   E  *--*   E--*  *              |  |      |     |      |  |              *--*      *--*--*      *--* PROG (Python) # Using graphillion from graphillion import GraphSet import graphillion.tutorial as tl def A333438(n):     universe = tl.grid(n - 1, n - 1)     GraphSet.set_universe(universe)     start, goal = 1, 2     paths = GraphSet.paths(start, goal)     return paths.len() * 2 print([A333438(n) for n in range(2, 10)]) CROSSREFS Cf. A271507, A333439. Sequence in context: A000513 A088027 A271267 * A232840 A113905 A200045 Adjacent sequences:  A333435 A333436 A333437 * A333439 A333440 A333441 KEYWORD nonn,more AUTHOR Seiichi Manyama, Mar 21 2020 STATUS approved

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Last modified August 11 07:36 EDT 2022. Contains 356055 sequences. (Running on oeis4.)