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 A289680 #13 Aug 04 2017 15:25:48 %S A289680 1,2,10,70,630,6864,87087,1254110,20128680,355185012,6817706350, %T A289680 141150702840,3130281211300,73933388090280,1850739337395090, %U A289680 48898191857790150,1358695827817964130,39579468688851814800,1205409232277565987210,38286822212810480963940,1265497066771343361031440 %N A289680 a(n) = Catalan(n+1)*Bell(n). %H A289680 Michael De Vlieger, <a href="/A289680/b289680.txt">Table of n, a(n) for n = 0..446</a> %H A289680 Paul Tarau, <a href="https://arxiv.org/abs/1608.03912">A Hiking Trip Through the Orders of Magnitude: Deriving Efficient Generators for Closed Simply-Typed Lambda Terms and Normal Forms</a>, arXiv preprint arXiv:1608.03912 [cs.PL], 2016. See Example 5. %t A289680 Array[CatalanNumber[# + 1] BellB[#] &, 21, 0] (* _Michael De Vlieger_, Aug 04 2017 *) %Y A289680 Cf. A000108, A000110, A064299, A289679. %K A289680 nonn %O A289680 0,2 %A A289680 _N. J. A. Sloane_, Aug 04 2017