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 A350756 #24 Dec 25 2024 02:02:12
%S A350756 1,3,6,30,90,180,210,420,630,1260,2520,6930,13860,27720,41580,83160,
%T A350756 138600,180180,360360,540540,1081080,1413720,2162160,3063060,6126120,
%U A350756 12252240,18378360,36756720,73513440,91891800,116396280,183783600,232792560,349188840
%N A350756 Integers whose number of divisors that are triangular numbers sets a new record.
%C A350756 Terms that are triangular: 1, 3, 6, 210, 630, 2162160, ...
%C A350756 The number of triangular divisors of a(n) is A007862(a(n)): 1, 2, 3, 5, 6, 7, 8, 9, 10, 12, ...
%e A350756 1260 has 36 divisors of which 12 are triangular numbers {1, 3, 6, 10, 15, 21, 28, 36, 45, 105, 210, 630}. No positive integer smaller than 1260 has as many as twelve triangular divisors; hence 1260 is a term.
%t A350756 max=0;Do[If[(d=Length@Select[Divisors@k,IntegerQ[(Sqrt[8#+1]-1)/2]&])>max,Print@k;max=d],{k,10^10}] (* _Giorgos Kalogeropoulos_, Jan 13 2022 *)
%o A350756 (PARI) lista(nn) = {my(r=0); for (n=1, nn, my(m = sumdiv(n, d, ispolygonal(d,3))); if (m>r, r=m; print1(n", ")));} \\ _Michel Marcus_, Jan 14 2022
%Y A350756 Cf. A000217, A007862, A130317.
%Y A350756 Similar for A046952 (squares), A053624 (odd), A093036 (palindromes), A181808 (even), A340548 (repdigits), A340549 (repunits) divisors.
%K A350756 nonn
%O A350756 1,2
%A A350756 _Bernard Schott_, Jan 13 2022