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 A180388 #14 Jun 10 2015 14:13:45 %S A180388 0,0,0,0,2,24,228,2088,19732,197890,2131060,24729108,309027560, %T A180388 4148115048,59611031304,913915160628,14897443573244,257369478424890, %U A180388 4698494631208500,90393611677083892,1828153614233855024,38778554791649355232,860921156414834534368 %N A180388 Number of permutations of 1..n with number of rises (p(i+1)>p(i)) different from number of rises in the inverse permutation. %H A180388 Vaclav Kotesovec, <a href="/A180388/b180388.txt">Table of n, a(n) for n = 0..200</a> %Y A180388 a(n) + A180389(n) = n! = A000142(n). %K A180388 nonn %O A180388 0,5 %A A180388 _Leroy Quet_, _D. S. McNeil_ and _R. H. Hardin_ in the Sequence Fans Mailing List Sep 01 2010 %E A180388 More terms from _Vaclav Kotesovec_, Jun 10 2015 %E A180388 a(0)=0 prepended by _Alois P. Heinz_, Jun 10 2015