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A333606 Number of directed Hamiltonian walks from NW to SW corners of a 10 X n grid.

%I A333606 #25 Jun 28 2023 16:27:25
%S A333606 1,1,256,1480,117852,1513468,71154709,1283569420,47001928863,
%T A333606 1013346943033,32440676063382,771708613086275,22928865477892898,
%U A333606 576390471202016758,16424125813587374688,425923820730159849603,11854446538789342310672,312866945593394069370317
%N A333606 Number of directed Hamiltonian walks from NW to SW corners of a 10 X n grid.
%H A333606 Ed Wynn, <a href="/A333606/b333606.txt">Table of n, a(n) for n = 1..68</a>
%o A333606 (Python)
%o A333606 # Using graphillion
%o A333606 from graphillion import GraphSet
%o A333606 import graphillion.tutorial as tl
%o A333606 def A271592(n, k):
%o A333606     if k == 1: return 1
%o A333606     universe = tl.grid(k - 1, n - 1)
%o A333606     GraphSet.set_universe(universe)
%o A333606     start, goal = 1, n
%o A333606     paths = GraphSet.paths(start, goal, is_hamilton=True)
%o A333606     return paths.len()
%o A333606 def A333606(n):
%o A333606     return A271592(10, n)
%o A333606 print([A333606(n) for n in range(1, 8)])
%Y A333606 Row n=10 of A271592.
%Y A333606 Cf. A333585.
%K A333606 nonn
%O A333606 1,3
%A A333606 _Seiichi Manyama_, Mar 28 2020
%E A333606 More terms from _Ed Wynn_, Jun 28 2023