Number of 2-distant 3-noncrossing partitions of {1,...,n}.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =15a(5) =52a(6) =203a(7) =876a(8) =4115a(9) =20765a(10) =111301a(11) =627821a(12) =3698873a(13) =22623354a(14) =142940629a(15) =929208778a(16) =6194162081a(17) =42223649277a(18) =293640007995