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 A072023 #23 Aug 08 2025 03:11:50 %S A072023 13,31,70,119,189,210,235,236,265,301,303,317,345,352,366,448,470,472, %T A072023 479,498,500,511,520,546,557,562,572,578,580,624,674,682,691,724,740, %U A072023 747,768,784,808,815,876,878,880,948,957,964,981,990,995,998,1017,1035,1044 %N A072023 Values of k such that A072022(k)=0. %C A072023 See A074915 for a bound on A048864(x) which allows the establishment of a suitable search range the terms of this sequence. - _Giovanni Resta_, Feb 25 2020 %H A072023 Giovanni Resta, <a href="/A072023/b072023.txt">Table of n, a(n) for n = 1..10000</a> %e A072023 13 is a term because a number whose RRS includes exactly 13 nonprime numbers doesn't exist. Phi(x) - Pi(x) + omega(x) = 13 has no solution. %t A072023 (* See A072022. *) %Y A072023 Cf. A048864, A072022, A074915, A000010, A000720, A001221. %K A072023 nonn %O A072023 1,1 %A A072023 _Labos Elemer_, Jun 06 2002 %E A072023 More terms (search up to 10^6) from _Michel Marcus_, Aug 08 2019 %E A072023 Terms a(51) and beyond from _Giovanni Resta_, Feb 25 2020