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A068313
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Number of different 0-1 matrices in which the number of 1's is n, with at least one 1 in each row and column.
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0
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1, 4, 15, 82, 457, 3231, 24055, 209375, 1955288, 20455936, 229830841, 2828166755, 37228913365, 528635368980, 7990596990430, 128909374528433, 2202090635802581, 39837079499488151, 759320365206705013
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| This is the sum over the matrix of base change from the elementary symmetric functions to the monomial symmetric functions
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REFERENCES
| I.G. Macdonald, Symmetric Functions and Hall Polynomials, Oxford 1979, p. 57
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EXAMPLE
| a(2) =4 because there 4 different 0-1 matrices of weight 2, these are 1 10 01 11,1, 01, 10
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CROSSREFS
| Sequence in context: A125307 A073479 A147690 * A174661 A207161 A203121
Adjacent sequences: A068310 A068311 A068312 * A068314 A068315 A068316
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KEYWORD
| nonn
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AUTHOR
| Axel Kohnert (axel.kohnert(AT)uni-bayreuth.de), Feb 25 2002
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