137272

Appears in sequences

• Number of possible values of C(v) = the number of valid mountain-valley assignments for a flat-foldable origami vertex v of degree 2n.at n=34A156209
• Number of undirected circular permutations i_0, i_1, ..., i_n of 0, 1, ..., n such that all the 2*n+2 numbers |i_0 +/- i_1|, |i_1 +/- i_2|, ..., |i_{n-1} +/- i_n|, |i_n +/- i_0| have the form (p-1)/2 with p an odd prime.at n=15A228956
• Largest even k such that h(-k) = 2n, where h(D) is the class number of the quadratic field with discriminant D; or 0 if no such k exists.at n=21A357573