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 A342806 #5 Mar 23 2021 13:05:23 %S A342806 15,21,78,300,528,903,990,1830,2628,3240,3570,4278,5253,5460,7503, %T A342806 8778,9870,13203,13530,16653,18528,20100,22578,24753,25200,29403, %U A342806 31878,37128,39903,45753,48828,55278,64980,65703,72390,73920,81003,88410,98790,106953,107880 %N A342806 Integers m such that A342805(m) = m+3. %e A342806 For m=15, A177028 row is (15, 6, 3); 6*3 = 18 and 18-3 = 15, so 15 is a term. %o A342806 (PARI) row(n)=my(v=List()); fordiv(2*n, k, if(k<2, next); if(k==n, break); my(s=(2*n/k-4+2*k)/(k-1)); if(denominator(s)==1, listput(v, s))); Vec(v); \\ A177028 %o A342806 f(n) = vecprod(row(n))/n; \\ A342805 %o A342806 isok(m) = f(m) == m+3; %Y A342806 Cf. A177028, A342805. %Y A342806 Subsequence of A090466. %K A342806 nonn %O A342806 1,1 %A A342806 _Michel Marcus_, Mar 22 2021