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A221145
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a(n) is the number of permutations of n elements with exactly one fixed point and no transpositions.
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1
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1, 0, 0, 8, 30, 144, 1120, 9120, 80892, 808640, 8908416, 106889760, 1389405160, 19452003648, 291782125440, 4668506495744, 79364583206160, 1428562661736960, 27142690917071872, 542853814698737280, 11399930105272855776, 250798462399704792320
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OFFSET
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1,4
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LINKS
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Table of n, a(n) for n=1..22.
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FORMULA
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Equals n*A038205(n-1). - Giovanni Resta, Nov 13 2012
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EXAMPLE
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For n = 4 the a(4) = 8 solutions are (123), (124), (132), (134), (142), (143), (234), (243)
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CROSSREFS
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Cf. A038205.
Sequence in context: A161222 A229374 A215471 * A098741 A027146 A302409
Adjacent sequences: A221142 A221143 A221144 * A221146 A221147 A221148
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KEYWORD
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nonn
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AUTHOR
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James Mahoney, Nov 13 2012
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EXTENSIONS
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Edited by N. J. A. Sloane, Jan 03 2013
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STATUS
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approved
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