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 A228670 #13 Sep 07 2014 06:07:29 %S A228670 1,0,0,19,68,110,1679,11941,59470,528974,4907480,36965659,370685663, %T A228670 4086527638,40650345653,458464525689,5857242113368,72283039099029, %U A228670 938515852729074,13416951764772945,194738851363141390,2909111655448399908,46421744844240409407 %N A228670 Number of permutations of [n] having a shortest ascending run of length 3. %H A228670 Alois P. Heinz and Vaclav Kotesovec, <a href="/A228670/b228670.txt">Table of n, a(n) for n = 3..480</a> (first 100 terms from Alois P. Heinz) %F A228670 a(n) ~ c * d^n * n!, where d = 0.63140578989563018836245602310621356272419174622597338..., c = 0.2944330707154006599431970237808940992565854768253334... . - _Vaclav Kotesovec_, Sep 07 2014 %e A228670 a(3) = 1: 123. %e A228670 a(6) = 19: 124356, 125346, 126345, 134256, 135246, 136245, 145236, 146235, 156234, 234156, 235146, 236145, 245136, 246135, 256134, 345126, 346125, 356124, 456123. %Y A228670 Column k=3 of A064315. %K A228670 nonn %O A228670 3,4 %A A228670 _Alois P. Heinz_, Aug 29 2013