This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A147580 #12 Dec 22 2020 02:14:11
%S A147580 4849845,14549535,24249225,33948915,43648605,53348295,63047985,
%T A147580 72747675,82447365,92147055,101846745,121246125,130945815,160044885,
%U A147580 169744575,189143955,218243025,237642405,247342095,266741475,276441165,305540235,315239925,363738375,373438065
%N A147580 Numbers with exactly 7 distinct odd prime divisors {3,5,7,11,13,17,19}.
%C A147580 Numbers k such that phi(k)/k = m
%C A147580 ( Family of sequences for successive n odd primes )
%C A147580 m=2/3 numbers with exactly 1 distinct prime divisor {3} see A000244
%C A147580 m=8/15 numbers with exactly 2 distinct prime divisors {3,5} see A033849
%C A147580 m=16/35 numbers with exactly 3 distinct prime divisors {3,5,7} see A147576
%C A147580 m=32/77 numbers with exactly 4 distinct prime divisors {3,5,7,11} see A147577
%C A147580 m=384/1001 numbers with exactly 5 distinct prime divisors {3,5,7,11,13} see A147578
%C A147580 m=6144/17017 numbers with exactly 6 distinct prime divisors {3,5,7,11,13,17} see A147579
%C A147580 m=3072/323323 numbers with exactly 7 distinct prime divisors {3,5,7,11,13,17,19} see A147580
%C A147580 m=110592/323323 numbers with exactly 8 distinct prime divisors {3,5,7,11,13,17,19,23} see A147581
%H A147580 Amiram Eldar, <a href="/A147580/b147580.txt">Table of n, a(n) for n = 1..10000</a>
%F A147580 Sum_{n>=1} 1/a(n) = 1/1658880. - _Amiram Eldar_, Dec 22 2020
%t A147580 a = {}; Do[If[EulerPhi[4849845 x] == 1658880 x, AppendTo[a, 4849845 x]], {x, 1, 100}]; a
%Y A147580 Cf. A060735, A143207, A147571-A147575, A147576-A147580.
%K A147580 nonn
%O A147580 1,1
%A A147580 _Artur Jasinski_, Nov 07 2008
%E A147580 More terms from _Amiram Eldar_, Mar 11 2020