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 A275100 #10 Jul 18 2023 16:11:29
%S A275100 1,5,16,64,298,1540,8506,48844,286498,1699300,10136746,60643324,
%T A275100 363328498,2178376660,13065476986,78378513004,470228031298,
%U A275100 2821239047620,16927046865226,101561118929884,609363226794898,3656168900416180,21936982021437466,131621797985445964
%N A275100 Number of set partitions of [3*n] such that within each block the numbers of elements from all residue classes modulo n are equal for n>0, a(0)=1.
%H A275100 Alois P. Heinz, <a href="/A275100/b275100.txt">Table of n, a(n) for n = 0..1000</a>
%H A275100 J.-M. Sixdeniers, K. A. Penson and A. I. Solomon, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL4/SIXDENIERS/bell.html">Extended Bell and Stirling Numbers From Hypergeometric Exponentiation</a>, J. Integer Seqs. Vol. 4 (2001), #01.1.4.
%H A275100 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (10,-27,18).
%F A275100 G.f.: -(21*x^3-7*x^2-5*x+1)/((x-1)*(6*x-1)*(3*x-1)).
%t A275100 CoefficientList[Series[-(21x^3-7x^2-5x+1)/((x-1)(6x-1)(3x-1)),{x,0,30}],x] (* _Harvey P. Dale_, Dec 15 2018 *)
%Y A275100 Row n=3 of A275043.
%K A275100 nonn,easy
%O A275100 0,2
%A A275100 _Alois P. Heinz_, Jul 16 2016