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 A156237 #11 Feb 16 2025 08:33:09
%S A156237 6,66,630,7140,103740,1272810,56812470,1722580860,48098217090,
%T A156237 1850186768430,139261952960130,17743036637876550,741902728913225880,
%U A156237 21549201398378163510,2378522762792139793830,351206814022419685159830
%N A156237 Smallest hexagonal number with n distinct prime factors.
%C A156237 a(18) <= 45781615623002935783197090. - _Donovan Johnson_, Feb 15 2012
%H A156237 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HexagonalNumber.html">Hexagonal Numbers</a>.
%e A156237 a(9) = 1722580860 = 2^2*3*5*7*11*13*23*29*43. 1722580860 is the smallest hexagonal number with 9 distinct prime factors.
%t A156237 Module[{nn=167*10^5,c},c={#,PrimeNu[#]}&/@PolygonalNumber[6,Range[nn]];Table[ SelectFirst[ c,#[[2]]==n&],{n,2,12}]][[;;,1]] (* The program generates the first 11 terms of the sequence. *) (* _Harvey P. Dale_, Jan 19 2024 *)
%Y A156237 Cf. A000384, A076551, A156236, A156238, A156239.
%K A156237 nonn
%O A156237 2,1
%A A156237 _Donovan Johnson_, Feb 07 2009