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Number of self-avoiding paths joining opposite corners of 7 X n board.
2

%I #10 Apr 06 2020 10:28:57

%S 1,64,1369,29739,752061,20562673,575780564,16230458696,459133264944,

%T 13021391001373,369886375079581,10516022622412960,299104709252534435,

%U 8509249843020438582,242108399244641421526,6888987223916209602814,196026708756588099010848

%N Number of self-avoiding paths joining opposite corners of 7 X n board.

%H Seiichi Manyama, <a href="/A333812/b333812.txt">Table of n, a(n) for n = 1..400</a>

%o (Python)

%o # Using graphillion

%o from graphillion import GraphSet

%o import graphillion.tutorial as tl

%o def A064298(n, k):

%o if n == 1 or k == 1: return 1

%o universe = tl.grid(n - 1, k - 1)

%o GraphSet.set_universe(universe)

%o start, goal = 1, k * n

%o paths = GraphSet.paths(start, goal)

%o return paths.len()

%o def A333812(n):

%o return A064298(n, 7)

%o print([A333812(n) for n in range(1, 20)])

%Y Row 7 of A064298.

%K nonn

%O 1,2

%A _Seiichi Manyama_, Apr 06 2020