1Math::NumSeq::TotientPeUrsfeerctC(o3n)tributed Perl DocuMmaetnht:a:tNiuomnSeq::TotientPerfect(3)
2
3
4
6 Math::NumSeq::TotientPerfect -- sum of repeated totients is N itself
7
9 use Math::NumSeq::TotientPerfect;
10 my $seq = Math::NumSeq::TotientPerfect->new;
11 my ($i, $value) = $seq->next;
12
14 Numbers for which the sum of repeated totients until reaching 1 gives
15 the starting n itself.
16
17 3, 9, 15, 27, 39, 81, 111, 183, 243, 255, ...
18
19 For example totient(15)=8, totient(8)=4, totient(4)=2 and totient(1)=1.
20 Adding them up 8+4+2+1=15 so 15 is a perfect totient.
21
22 The current implementation of "next()" is merely a search by "pred()"
23 through all odd integers, which isn't very fast.
24
26 See "FUNCTIONS" in Math::NumSeq for behaviour common to all sequence
27 classes.
28
29 "$seq = Math::NumSeq::TotientPerfect->new ()"
30 Create and return a new sequence object.
31
32 "$bool = $seq->pred($value)"
33 Return true if $value is a perfect totient.
34
36 Math::NumSeq, Math::NumSeq::Totient, Math::NumSeq::TotientSteps
37
39 <http://user42.tuxfamily.org/math-numseq/index.html>
40
42 Copyright 2011, 2012, 2013, 2014, 2016, 2019 Kevin Ryde
43
44 Math-NumSeq is free software; you can redistribute it and/or modify it
45 under the terms of the GNU General Public License as published by the
46 Free Software Foundation; either version 3, or (at your option) any
47 later version.
48
49 Math-NumSeq is distributed in the hope that it will be useful, but
50 WITHOUT ANY WARRANTY; without even the implied warranty of
51 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
52 General Public License for more details.
53
54 You should have received a copy of the GNU General Public License along
55 with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.
56
57
58
59perl v5.32.0 2020-07-28 Math::NumSeq::TotientPerfect(3)