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%I #11 Nov 25 2020 00:50:40
%S 36,4040,542295,51139577,4237530095,345142437669,28251882697663,
%T 2318527339461265,190273063549680295,15609156135669687673,
%U 1280305089790914190288,105011610206669201362004,8613171107463963712000106,706463610718638922253288622,57945052730138702492774189915
%N Number of cycles in the grid graph P_9 X P_n.
%H Seiichi Manyama, <a href="/A339121/b339121.txt">Table of n, a(n) for n = 2..150</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GraphCycle.html">Graph Cycle</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GridGraph.html">Grid Graph</a>
%o (Python)
%o # Using graphillion
%o from graphillion import GraphSet
%o import graphillion.tutorial as tl
%o def A(n, k):
%o universe = tl.grid(n - 1, k - 1)
%o GraphSet.set_universe(universe)
%o cycles = GraphSet.cycles()
%o return cycles.len()
%o def A339121(n):
%o return A(n, 9)
%o print([A339121(n) for n in range(2, 15)])
%Y Cf. A140517, A231829.
%K nonn
%O 2,1
%A _Seiichi Manyama_, Nov 24 2020
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