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 A276281 #16 Sep 23 2016 02:44:57
%S A276281 1,2,4,5,10,15,25,30,52,75,104,203,225,260,406,780,877,1015,1754,2704,
%T A276281 3045,4140,4385,8280,10556,13155,20700,21147,41209,42294,45604,62100,
%U A276281 105735,115975,178031,215280,231950,317205,579875,678570,769129,840420,1099644
%N A276281 Numbers of the form Bell(i)*Bell(j).
%H A276281 Vincenzo Librandi, <a href="/A276281/b276281.txt">Table of n, a(n) for n = 1..200</a>
%t A276281 Take[Union@Flatten@Table[BellB[i] BellB[j], {i, 0, 60}, {j, i}], 60]
%o A276281 (Perl) use ntheory ":all"; my($l,$i,%BP)=(50,0); my @Bell = map { my $n=$_; vecsum(map { stirling($n,$_,2) } 0..$n); } 0..$l; for my $i (0..$l) { for my $j ($i..$l) { $BP{vecprod($Bell[$i],$Bell[$j])}++ } } say $i++," $_" for sort {$a<=>$b} keys %BP; # _Dana Jacobsen_, Sep 07 2016
%Y A276281 Cf. A000110, A049997, A272909.
%K A276281 nonn,easy
%O A276281 1,2
%A A276281 _Vincenzo Librandi_, Sep 04 2016