380653domain: NAppears in sequencesNumber of set partitions of [n] such that all absolute differences between least elements of consecutive blocks and between consecutive elements within the blocks are not larger than four.at n=12A287583Expansion of Product_{k>0} (1 + (2*k-1)*x^(2*k-1))/(1 - 2*k*x^(2*k)).at n=24A319859