Number of permutations p of [n] such that |p(i) - p(i-1)| <= 3 and |p(i) - p(i-2)| <= 4.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =72a(6) =124a(7) =210a(8) =394a(9) =810a(10) =1652a(11) =3168a(12) =5816a(13) =10640a(14) =19794a(15) =37292a(16) =70298a(17) =131618a(18) =245146a(19) =456430a(20) =851670a(21) =1592008a(22) =2976326a(23) =5559808a(24) =10379010a(25) =19374184a(26) =36175422a(27) =67562524a(28) =126185322a(29) =235650426