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A217327
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Number of self-inverse permutations in S_n with longest increasing subsequence of length 7.
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2
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1, 7, 55, 319, 1904, 10275, 56135, 294386, 1556323, 8086433, 42298721, 219795160, 1149139210, 5999688692, 31506046052, 165664633982, 875886376212, 4643488263933, 24746018418741, 132328997879066, 711142850556217, 3836134976520394, 20791024498584110
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OFFSET
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7,2
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COMMENTS
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Also the number of Young tableaux with n cells and 7 rows.
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LINKS
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FORMULA
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EXAMPLE
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a(7) = 1: 1234567.
a(8) = 7: 12345687, 12345768, 12346578, 12354678, 12435678, 13245678, 21345678.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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