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Search: id:A067240
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| A067240 |
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If n = Prod p_i^e_i, a(n) = Sum (p_i-1)*p_i^(e_i-1). |
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+0
3
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| 0, 1, 2, 2, 4, 3, 6, 4, 6, 5, 10, 4, 12, 7, 6, 8, 16, 7, 18, 6, 8, 11, 22, 6, 20, 13, 18, 8, 28, 7, 30, 16, 12, 17, 10, 8, 36, 19, 14, 8, 40, 9, 42, 12, 10, 23, 46, 10, 42, 21, 18, 14, 52, 19, 14, 10, 20, 29, 58, 8, 60, 31, 12, 32, 16, 13, 66, 18, 24, 11, 70
(list; graph; listen)
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OFFSET
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1,3
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REFERENCES
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J. Kuzmanovich and A. Pavlichenkov, Finite groups of matrices whose entries are integers, Amer. Math. Monthly, 109 (2002), 173-186. (T on p. 181.)
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FORMULA
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a(n) = Sum phi(p_i^e_i). - T. D. Noe (noe(AT)sspectra.com), Jul 10 2003
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MAPLE
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with(numtheory); A067240 := proc(n) local e, j; e := ifactors(n)[2]: add((e[j][1]-1)*e[j][1]^(e[j][2]-1), j=1..nops(e)); end;
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CROSSREFS
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Sequence in context: A113885 A113886 A122376 this_sequence A126080 A060681 A161660
Adjacent sequences: A067237 A067238 A067239 this_sequence A067241 A067242 A067243
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Mar 10 2002
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