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 A299790 #49 Feb 14 2019 12:30:05
%S A299790 3,9,15,21,26,29,34,35,38,39,43,45,50,51,54,57,62,69,74,86,87,90,98,
%T A299790 101,103,107,110,111,114,118,123,124,134,135,137,142,146,151,152,155,
%U A299790 158,161,163,170,173,174,179,186,188,189,191,194,197,206,214,218,220,221,227,229,230,231,237,239,242,244,246,248
%N A299790 Positive integers that do not equal any number minus its number of factorizations.
%o A299790 (PARI) fcnt(n, m) = {local(s); s=0; if(n == 1, s=1, fordiv(n, d, if(d > 1 & d <= m, s=s+fcnt(n/d, d)))); s};
%o A299790 f(n) = n - fcnt(n, n);
%o A299790 is(n) = j=1;x=2^(floor(log(n)/log(2))+2);while(j<x&&f(j)!=n,j++);f(j)!=n; \\ _Jinyuan Wang_, Feb 14 2019
%Y A299790 Cf. A001055 (number of factorizations).
%K A299790 nonn
%O A299790 1,1
%A A299790 _Aidan Clarke_, Jan 21 2019
%E A299790 More terms from _Jinyuan Wang_, Feb 14 2019