

A185179


Irregular triangle, read by rows, of the A185178(n) values of the permanent of an n X n (0,1)matrix (n>=3) with exactly three 1's in each row and each column.


3



6, 9, 12, 13, 17, 18, 20, 36, 24, 25, 26, 27, 30, 31, 32, 54, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 44, 45, 48, 49, 52, 72, 78, 81
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OFFSET

3,1


REFERENCES

V. I. Bolshakov, On spectrum of permanent on Lambda_n^k, Proc. of Seminar on Discrete Math. and Appl., Moscow State Univ. (1986), 6573 (in Russian).


LINKS

Table of n, a(n) for n=3..36.
V. S. Shevelev, Some problems of the theory of enumerating the permutations with restricted position, Journal of Soviet Mathematics, 61 (4) (1992) 22722317 (see pp. 23072309).


EXAMPLE

Triangle begins:
6
9
12, 13
17, 18, 20, 36
24, 25, 26, 27, 30, 31, 32, 54,
33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 44, 45, 48, 49, 52, 72, 78, 81


CROSSREFS

Cf. A185178, A185177, A176211, A176212.
Sequence in context: A081392 A225868 A185177 * A072546 A295670 A272466
Adjacent sequences: A185176 A185177 A185178 * A185180 A185181 A185182


KEYWORD

nonn,tabf,hard,more


AUTHOR

Vladimir Shevelev, Feb 19 2011


STATUS

approved



