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 A032095 #13 Sep 12 2013 12:26:09
%S A032095 1,1,2,10,32,126,452,1716,6400,24310,92252,352716,1351616,5200300,
%T A032095 20056584,77558760,300533760,1166803110,4537543340,17672631900,
%U A032095 68923172032,269128937220,1052049129144,4116715363800
%N A032095 Number of reversible strings with n-1 black beads and n-1 white beads. String is not palindromic.
%H A032095 C. G. Bower, <a href="/transforms2.html">Transforms (2)</a>
%F A032095 "BHK[ n ](2n-1)" (reversible, identity, unlabeled, n parts, 2n-1 elements) transform of 1, 1, 1, 1...
%F A032095 for n>1 a(n)=(1/2)*C(2n-2, n-1) if n is even, a(n)=(1/2)[C(2n-2, n-1)-C(n-1, (n-1)/2)] if n is odd. (_Emeric Deutsch_ Jul 25 2002)
%F A032095 E.g.f. : 1+exp(x)*sinh(x)*BesselI(0,2x). [From _Paul Barry_, Aug 11 2009]
%t A032095 Join[{1},Table[If[EvenQ[n],Binomial[2n-2,n-1]/2,(Binomial[2n-2,n-1]- Binomial[ n-1,(n-1)/2])/2],{n,2,30}]] (* _Harvey P. Dale_, Sep 12 2013 *)
%Y A032095 Central column of triangle A034877.
%K A032095 nonn
%O A032095 1,3
%A A032095 _Christian G. Bower_