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Search: id:A006148
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| A006148 |
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Number of 4 X n binary matrices.
(Formerly M3919)
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+0
14
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| 1, 5, 22, 87, 317, 1053, 3250, 9343, 25207, 64167, 155004, 357009, 787586, 1670643, 3419552, 6774765, 13027340, 24372942, 44462456, 79240762, 138204782, 236258358, 396409924, 653639898, 1060379169, 1694174350, 2668300758
(list; graph; listen)
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OFFSET
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0,2
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
M. A. Harrison, On the number of classes of binary matrices, IEEE Trans. Computers, 22 (1973), 1048-1051.
A. Kerber, Experimentelle Mathematik, S\'{e}minaire Lotharingien de Combinatoire. Institut de Recherche Math. Avanc\'{e}e, Universit\'{e} Louis Pasteur, Strasbourg, Actes 19 (1988), 77-83.
B. Misek, On the number of classes of strongly equivalent incidence matrices. (Czech) Casopis Pest. Mat. 89 1964 211-218.
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LINKS
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Vladeta Jovovic, Binary matrices up to row and column permutations
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FORMULA
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G.f.: (x^20 - x^19 + 4*x^18 + 9*x^17 + 23*x^16 + 39*x^15 + 90*x^14 + 131*x^13 + 204*x^12 + 238*x^11 + 252*x^10 + 238*x^9 + 204*x^8 + 131*x^7 + 90*x^6 + 39*x^5 + 23*x^4 + 9*x^3 + 4*x^2 - x + 1)/((1 - x^4)^3*(1 - x^3)^4*(1 - x^2)^3*(1 - x)^6).
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CROSSREFS
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Cf. A002623, A002727.
Sequence in context: A058750 A058752 A122058 this_sequence A086090 A037529 A108072
Adjacent sequences: A006145 A006146 A006147 this_sequence A006149 A006150 A006151
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KEYWORD
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nonn,nice
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
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More terms and g.f. from Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 04 2000
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