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 A246254 #10 Aug 26 2014 17:06:12 %S A246254 14708695606607601165843,3541988733308075285027550, %T A246254 503174667865819228904767230,54504030281627517895808563770, %U A246254 4983196403246326034913729334260,405629500925435775383214597193020,30367312487678851547450846684842845,2136522202012396295876641497958908090 %N A246254 Number of permutations of [n] with exactly nine occurrences of the consecutive step pattern up, down, down. %H A246254 Alois P. Heinz, <a href="/A246254/b246254.txt">Table of n, a(n) for n = 28..160</a> %F A246254 a(n) ~ c * (3*sqrt(3)/(2*Pi))^n * n! * n^9, where c = 0.0000000002026268159682390665... = c0 * (c0-1)^9 / (3^9 * 9!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - _Vaclav Kotesovec_, Aug 26 2014 %Y A246254 Column k=9 of A242819. %K A246254 nonn %O A246254 28,1 %A A246254 _Alois P. Heinz_, Aug 20 2014