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 A303931 #7 May 03 2018 14:33:22 %S A303931 1,0,1,1,2,2,5,6,14,22,51,95,232,498,1239,2953,7520,18920,49235, %T A303931 127917,338094,896060,2397627,6439730,17403252,47207620,128628877, %U A303931 351676075,964909660,2655474962,7329668097,20285420790,56284927718,156539620498,436343744531 %N A303931 Number of noncrossing partitions up to rotation and reflection of an n-set without singleton blocks. %H A303931 Andrew Howroyd, <a href="/A303931/b303931.txt">Table of n, a(n) for n = 0..200</a> %o A303931 (PARI) \\ See A303875 for NCPartitionsModDihedral %o A303931 Vec(NCPartitionsModDihedral(vector(40, k, k>1))) \\ _Andrew Howroyd_, May 02 2018 %Y A303931 Column k=0 of A211359. %Y A303931 Cf. A295198, A303875. %K A303931 nonn %O A303931 0,5 %A A303931 _Andrew Howroyd_, May 02 2018