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A077219
Floor(geometric mean of the reduced residue system modulo n).
0
1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 9, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 12, 12, 13, 14, 14, 14, 14, 15, 15, 16, 16, 16, 16, 17, 17, 18, 18, 18, 19, 20, 19, 20, 20, 20, 21, 22, 22, 23, 22, 23, 23, 23, 24, 25, 25, 25, 25, 26, 26, 27, 27, 27, 27, 28, 28
OFFSET
1,5
COMMENTS
1. The reduced residue system modulo n is the set of integers k between 1 and n which are coprime to n. The geometric mean of the positive integers a_1,...,a_n is the n-th root of a_1*...*a_n. 2. The arithmetic mean of the reduced residue system modulo n is A065033.
MATHEMATICA
gm[l_] := Module[{k, p}, k = Length[l]; p = Product[l[[i]], {i, 1, k}]; p^(1/k)]; rp[n_] := Module[{a, i}, a = {1}; For[i = 2, i < n, i++, If[GCD[i, n] == 1, a = Append[a, i]]]; a];
CROSSREFS
Sequence in context: A192262 A026414 A353090 * A026405 A226033 A054404
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Nov 30 2002
STATUS
approved