1Math::NumSeq::DedekindPUssieCrumCuolnattriivbeu(t3e)d PeMralthD:o:cNuummeSnetqa:t:iDoendekindPsiCumulative(3)
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6 Math::NumSeq::DedekindPsiCumulative -- cumulative Psi function
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9 use Math::NumSeq::DedekindPsiCumulative;
10 my $seq = Math::NumSeq::DedekindPsiCumulative->new;
11 my ($i, $value) = $seq->next;
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14 The cumulative Dedekind Psi function,
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16 1, 4, 8, 14, 20, 32, 40, 52, 64, 82, 94, 118, ...
17 starting i=1
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19 value = sum n=1 to n=i of Psi(n)
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21 where the Psi function is
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23 Psi(n) = product (p+1) * p^(e-1)
24 prime factors p^e in n
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26 The p+1 means one copy of each distinct prime in n is changed from p to
27 p+1. This is similar to Euler's totient function phi(n) (see
28 Math::NumSeq::Totient) but phi(n) is p-1 instead of p+1.
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31 See "FUNCTIONS" in Math::NumSeq for behaviour common to all sequence
32 classes.
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34 "$seq = Math::NumSeq::DedekindPsiCumulative->new ()"
35 Create and return a new sequence object.
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37 "$i = $seq->value_to_i_estimate($value)"
38 Return an estimate of the i corresponding to $value. Currently
39 this is based on the asymptotic
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41 value = 15*n^2/(2*Pi^2) + O(n*log(n))
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43 which neglecting the O(n*log(n)) becomes
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45 i ~= sqrt(value) * pi/sqrt(15/2)
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48 Math::NumSeq, Math::NumSeq::DedekindPsiSteps,
49 Math::NumSeq::TotientCumulative
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52 <http://user42.tuxfamily.org/math-numseq/index.html>
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55 Copyright 2012, 2013, 2014, 2016 Kevin Ryde
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57 Math-NumSeq is free software; you can redistribute it and/or modify it
58 under the terms of the GNU General Public License as published by the
59 Free Software Foundation; either version 3, or (at your option) any
60 later version.
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62 Math-NumSeq is distributed in the hope that it will be useful, but
63 WITHOUT ANY WARRANTY; without even the implied warranty of
64 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
65 General Public License for more details.
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67 You should have received a copy of the GNU General Public License along
68 with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.
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72perl v5.30.0 2019-08M-a0t5h::NumSeq::DedekindPsiCumulative(3)