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A174580
Let J_n be an n X n matrix which contains 1's only, I = I_n be the n X n identity matrix, and P = P_n be the incidence matrix of the cycle (1,2,3,...,n). Then a(n) is the number of (0,1,2) n X n matrices A <= 2(J_n - I - P) with exactly one 1 and one 2 in every row and column.
4
0, 2, 36, 1462, 83600, 5955474
OFFSET
3,2
REFERENCES
V. S. Shevelev, Development of the rook technique for calculating the cyclic indicators of (0,1)-matrices, Izvestia Vuzov of the North-Caucasus region, Nature sciences 4 (1996), 21-28 (in Russian).
S. E. Grigorchuk, V. S. Shevelev, An algorithm of computing the cyclic indicator of couples discordant permutations with restricted position, Izvestia Vuzov of the North-Caucasus region, Nature sciences 3 (1997), 5-13 (in Russian).
CROSSREFS
KEYWORD
nonn,more,uned
AUTHOR
Vladimir Shevelev, Mar 23 2010
STATUS
approved