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 A212258 #18 Nov 05 2020 05:30:50 %S A212258 0,0,1,6,25,105,490,2548,14698,93420,649715,4912776,40154387, %T A212258 352937312,3320636540,33305992320,354819046132,4001699525376, %U A212258 47637151241125,596958623741440,7855611484697773,108314507544748032,1561635447992241230,23498865431367684096 %N A212258 Number of binary increasing trees with n nodes and "min-path" of length 4. %H A212258 Filippo Disanto, <a href="http://arxiv.org/abs/1202.1139">André permutations of the second kind associated to strictly binary increasing trees and left to right minima in their sub-permutations</a>, arXiv preprint arXiv:1202.1139 [math.CO], 2012-2014. %Y A212258 A diagonal of A186366. %K A212258 nonn %O A212258 2,4 %A A212258 _N. J. A. Sloane_, May 11 2012 %E A212258 More terms from _Alois P. Heinz_, Apr 03 2014