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 A246253 #10 Aug 26 2014 17:05:31 %S A246253 4736552519729393091,925712659777722254622,108450427756505074280046, %T A246253 9790367872313042801164557,752566904329661335915465770, %U A246253 51895294413875186427307822050,3313685917841456847408819072255,200074814234955942882986408262750,11591748407639299505418556743604770 %N A246253 Number of permutations of [n] with exactly eight occurrences of the consecutive step pattern up, down, down. %H A246253 Alois P. Heinz, <a href="/A246253/b246253.txt">Table of n, a(n) for n = 25..160</a> %F A246253 a(n) ~ c * (3*sqrt(3)/(2*Pi))^n * n! * n^8, where c = 0.00000000566049683079281633... = c0 * (c0-1)^8 / (3^8 * 8!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - _Vaclav Kotesovec_, Aug 26 2014 %Y A246253 Column k=8 of A242819. %K A246253 nonn %O A246253 25,1 %A A246253 _Alois P. Heinz_, Aug 20 2014