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 A350193 #14 Dec 20 2021 03:57:10
%S A350193 0,1,5,7,22,33,124,187,757,852,876,1149,1541,5951,6767,8454,10067,
%T A350193 15555,20272,29751,51721,59662,89055,90088,92489,161673,207737,217341,
%U A350193 225622,361054,452639,530990,560684,669999,733454,1000067,1866828,2090121,2464677,3148962
%N A350193 Indices that give distinct values of A350090 in the order in which they appear.
%t A350193 With[{s = Table[Count[Range[0, n - 1], _?(IntegerQ@ Sqrt[4 # + 1] &[(3 n (n + 1) + 1) - (3 # (# + 1) + 1)] &)], {n, 0, 2^10}]}, Map[-1 + FirstPosition[s, #][[1]] &, DeleteDuplicates@ s]] (* _Michael De Vlieger_, Dec 19 2021, after _Amiram Eldar_ at A350090 *)
%Y A350193 Cf. A002378, A003215, A350090, A350120, A350192.
%K A350193 nonn
%O A350193 1,3
%A A350193 _Michel Marcus_, Dec 19 2021
%E A350193 a(1) = 0 inserted by and more terms from _Jinyuan Wang_, Dec 19 2021