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 A300737 #12 Apr 15 2018 13:29:18 %S A300737 3,5,7,8,9,11,13,14,15,17,19,20,21,23,24,25,26,27,29,31,32,33,35,37, %T A300737 38,39,41,43,44,45,47,48,49,50,51,53,54,55,56,57,59,61,62,63,64,65,67, %U A300737 68,69,71,73,74,75,77,79,80,81,83,84,85,86,87,89,90,91,92,93,95,97,98,99,101 %N A300737 Numbers of the form (k*i + 1)*(k*j - 1) with i, j >= 1 and k >= 2. %o A300737 (PARI) limit=100; v=vector(limit); for(n=0,limit, for(k=2,floor(limit^(1/2)), for(i=1,limit/k, for(j=1,limit/k,if(n==(k*i+1)*(k*j-1),v[n]=1,))))); for(n=1,limit,if(v[n],print1(n", "))) %Y A300737 Cf. A056868. %K A300737 nonn %O A300737 1,1 %A A300737 _Gionata Neri_, Mar 11 2018