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 A370061 #8 Feb 09 2024 14:22:44 %S A370061 1,1,4,6,26,45,204,380,1771,3450,16380,32886,158224,324632,1577532, %T A370061 3290040,16112057,34034715,167710664,357919100,1772645420,3815041230, %U A370061 18974357220,41124015036,205263418941,447534498320,2240623268512,4910258796240,24648785802336,54257308779600 %N A370061 Number of achiral dissections of a polygon into n hexagons by nonintersecting diagonals rooted at a cell. %H A370061 Andrew Howroyd, <a href="/A370061/b370061.txt">Table of n, a(n) for n = 1..1000</a> %F A370061 a(2*n) = 6*binomial(5*n+1, n-1)/(5*n+1); a(2*n+1) = 4*binomial(5*n+4, n)/(5*n+4). %o A370061 (PARI) a(n)=my(m=n\2); if(n%2==0, 6*binomial(5*m+1, m-1)/(5*m+1), 4*binomial(5*m+4, m)/(5*m+4)) %Y A370061 Column k=6 of A370060. %K A370061 nonn %O A370061 1,3 %A A370061 _Andrew Howroyd_, Feb 08 2024