62174764665domain: NAppears in sequencesa(n) = Sum[2^(A047260(i)-1), {i,1,n}].at n=23A113828Numbers that generate rotationally symmetrical XOR-triangles with a pattern of zero-triangles of edge length 3, some of which are clipped to result in some zero-triangles of edge length 2 at the edges.at n=9A334932