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Search: id:A006186
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| A006186 |
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Number of pair-coverings with largest block size 4.
(Formerly M3773)
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+0
1
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OFFSET
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4,2
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COMMENT
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The g.f. (1+5*z+6*z**2+z**3)/(z-1)/(z**2-z-1) conjectured by S. Plouffe in his 1992 dissertation is probably wrong.
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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).
R. G. Stanton, J. L. Allston and D. D. Cowan, Pair-coverings with restricted largest block length, Ars Combin., 11 (1981), 85-98.
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LINKS
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S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.
S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.
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CROSSREFS
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Sequence in context: A051220 A102785 A127493 this_sequence A121901 A156288 A049195
Adjacent sequences: A006183 A006184 A006185 this_sequence A006187 A006188 A006189
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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