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Search: id:A089179
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| A089179 |
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Number of equivalence classes of permutations of n letters, where the relation is that f and g are equivalent if every cycle of f is a power of some cycle of g. |
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+0
1
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| 1, 2, 6, 20, 85, 402, 2464, 15752, 119655, 976190, 9331894, 91769988, 1077214879, 12570658310, 168390947820, 2337860163248, 35513649943201, 544140329564898, 9660558198790510, 166372364728477220
(list; graph; listen)
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OFFSET
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1,2
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REFERENCES
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Albert Nijenhuis, Amer. Math. Monthly, 82 (1975), Solution to Problem 5932, pp. 86-87.
R. P. Stanley, Amer. Math. Monthly, 80 (1973), Problem 5932, p. 949.
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FORMULA
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E.g.f. x*exp(Sum( x^n/(n*phi(n)), n=1..infinity )) (phi is Euler's totient function). a(n) = n* A003510(n-1). - Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 15 2006
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MATHEMATICA
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yy[nn_] := CoefficientList[Normal[Series[Exp[Sum[x^n t[n]/(n), {n, 1, nn}]], {x, 0, nn}]], x]; zz[nn_] := Table[Simplify[yy[nn][[m]] m! ], {m, 1, nn}]; zz[10] will then give the first 10 values, e.g.
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CROSSREFS
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Sequence in context: A108124 A117574 A115084 this_sequence A004104 A079468 A124382
Adjacent sequences: A089176 A089177 A089178 this_sequence A089180 A089181 A089182
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KEYWORD
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easy,nonn
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AUTHOR
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Herb Wilf (wilf(AT)math.upenn.edu), Dec 08 2003
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EXTENSIONS
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More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 15 2006
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