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 A270766 #5 Mar 22 2016 18:21:29
%S A270766 2,9,41,195,979,5204,29278,174029,1090335,7182335,49620133,358677988,
%T A270766 2706692878,21279580773,173959285361,1476140369523,12980688801711,
%U A270766 118115459494648,1110587753256570,10776530860299409,107787449481730311,1110043901404359391
%N A270766 Total sum of the sizes of all blocks with minimal element 3 in all set partitions of {1,2,...,n}.
%H A270766 Alois P. Heinz, <a href="/A270766/b270766.txt">Table of n, a(n) for n = 3..575</a>
%H A270766 Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a>
%Y A270766 Column k=3 of A270702.
%Y A270766 A diagonal of A270701.
%K A270766 nonn
%O A270766 3,1
%A A270766 _Alois P. Heinz_, Mar 22 2016