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 A060015 Sum of orders of all even permutations of n letters. 5
 1, 1, 7, 31, 211, 1411, 12601, 137047, 1516831, 18111751, 223179001, 2973194071, 46287964867, 835826439631, 15722804528341, 292673102609791, 5177400032329231, 102538737981192607, 2284570602107946601 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 REFERENCES Joshua Harrington, Lenny Jones, and Alicia Lamarche, Characterizing Finite Groups Using the Sum of the Orders of the Elements, International Journal of Combinatorics, Volume 2014, Article ID 835125, 8 pages; http://dx.doi.org/10.1155/2014/835125 LINKS EXAMPLE For n = 4 there is 1 even permutation (1) of order 1, 3 even permutations (12)(34) etc. of order 2 and 8 (123) etc. of order 3, for a total of 31. MATHEMATICA g[list_]:=Total[list]!/Apply[Times, list]/Apply[Times, Table[Count[list, n]!, {n, 1, 20}]]; f[list_]:=Apply[Plus, Table[Count[list, n], {n, 2, 20, 2}]]; Map[Total, Table[Map[g, Select[Partitions[n], EvenQ[f[#]]&]]*Map[Apply[LCM, #]&, Select[Partitions[n], EvenQ[f[#]]&]], {n, 1, 20}]]  (* Geoffrey Critzer, Mar 26 2013 *) CROSSREFS Cf. A060014. Sequence in context: A155521 A201116 A329944 * A261558 A241456 A094711 Adjacent sequences:  A060012 A060013 A060014 * A060016 A060017 A060018 KEYWORD nonn,nice,easy AUTHOR N. J. A. Sloane, Mar 17 2001 EXTENSIONS More terms from Vladeta Jovovic, Mar 18 2001 STATUS approved

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Last modified December 8 03:17 EST 2021. Contains 349590 sequences. (Running on oeis4.)