A174564 Let J_n be 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 (2,3,...,n,1). Then a(n) is the number of (0,1) n X n matrices A<=J_n-I-P with exactly two 1's in every row and column

0, 1, 13, 522, 27828, 1867363

Offset

3,3

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).

Links

Table of n, a(n) for n=3..8.

Crossrefs

Cf. A001499 A007107 A082491 A000186

Sequence in context: A095883 A363868 A139168 * A300525 A295942 A297518

Adjacent sequences: A174561 A174562 A174563 * A174565 A174566 A174567

Keyword

nonn,uned

Author

Vladimir Shevelev, Mar 22 2010

Status

approved