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 A358539 #21 Feb 16 2025 08:34:04
%S A358539 6,36,210,1260,6426,3360,351000,207900,3749460,1153152,15036840,
%T A358539 204204000,213825150,11737440,91797866160,1006485480,2310808500,
%U A358539 4966241280,22651328700,325269404460,14266470332400,11203920000,256653797400,45843256859400,59207908359600,46822406400
%N A358539 a(n) is the smallest number with exactly n divisors that are n-gonal numbers.
%H A358539 Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/figuratedivisors.py">Python program</a>.
%H A358539 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PolygonalNumber.html">Polygonal Number</a>
%H A358539 <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a>
%e A358539 a(5) = 210 because 210 has 5 pentagonal divisors {1, 5, 35, 70, 210} and this is the smallest such number.
%o A358539 (PARI) a(n) = my(k=1); while (sumdiv(k, d, ispolygonal(d, n)) != n, k++); k; \\ _Michel Marcus_, Nov 21 2022
%Y A358539 Cf. A005179, A130279, A130317, A356132, A358540, A358541.
%K A358539 nonn
%O A358539 3,1
%A A358539 _Ilya Gutkovskiy_, Nov 21 2022
%E A358539 a(12)-a(13) from _Michel Marcus_, Nov 21 2022
%E A358539 a(14)-a(16) from _Daniel Suteu_, Dec 04 2022
%E A358539 a(17)-a(28) from _Martin Ehrenstein_, Dec 05 2022