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 A330703 #9 Jun 13 2020 03:23:12 %S A330703 6,9,12,14,18,20,33,44,62,70,92,108,116,138,164,175,212,254,280,308, %T A330703 320,332,348,356,452,490,524,558,572,692,716,764,833,932,956,1004, %U A330703 1105,1124,1172,1188,1436,1496,1562,1593,1676,1724,1772,1964,2002,2036,2088,2132 %N A330703 Numbers k such that psi(k) = psi(k + 2) where psi(k) is the Dedekind psi function (A001615). %H A330703 Amiram Eldar, <a href="/A330703/b330703.txt">Table of n, a(n) for n = 1..10000</a> %H A330703 Jozsef Sandor, <a href="https://www.emis.de/journals/JIPAM/article546.html">On the composition of some arithmetic functions, II</a>, Journal of Inequalities in Pure and Applied Mathematics, Vol. 6, No. 3 (2005), Article 73. %e A330703 6 is in the sequence since psi(6) = psi(8) = 12. %t A330703 psi[1] = 1; psi[n_] := n * Times @@ (1 + 1/Transpose[FactorInteger[n]][[1]]); Select[Range[10^3], psi[#] == psi[# + 2] &] %Y A330703 Cf. A001494, A001615, A007373, A062832, A291043. %K A330703 nonn %O A330703 1,1 %A A330703 _Amiram Eldar_, Dec 26 2019