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 A086148 Sum of the orders of the elements in the dihedral group D_2n. 1
 3, 7, 13, 19, 31, 33, 57, 59, 79, 83, 133, 101, 183, 157, 177, 203, 307, 219, 381, 271, 343, 377, 553, 349, 571, 523, 601, 529, 871, 501, 993, 747, 843, 887, 973, 743, 1407, 1105, 1177, 983, 1723, 987, 1893, 1309, 1371, 1613, 2257, 1293, 2199, 1663, 2013 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 FORMULA a(n) = 2*n + Sum_{d|n} d*phi(d). - Vladeta Jovovic, Aug 27 2003 MATHEMATICA f[p_, e_] := (p^(2*e+1)+1)/(p+1); a[1] = 3; a[n_] := 2*n + Times @@ (f @@@ FactorInteger[n]); Array[a, 50] (* Amiram Eldar, Jul 31 2019 *) CROSSREFS Cf. A057660. Sequence in context: A171747 A031215 A099957 * A262086 A205956 A215907 Adjacent sequences:  A086145 A086146 A086147 * A086149 A086150 A086151 KEYWORD nonn AUTHOR Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 25 2003 EXTENSIONS More terms from Vladeta Jovovic, Aug 27 2003 STATUS approved

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Last modified October 15 07:46 EDT 2019. Contains 328026 sequences. (Running on oeis4.)