Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={1}.

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =9a(5) =19a(6) =38a(7) =84a(8) =193a(9) =430a(10) =940a(11) =2074a(12) =4609a(13) =10223a(14) =22611a(15) =50022a(16) =110780a(17) =245348a(18) =543189a(19) =1202511a(20) =2662417a(21) =5894961a(22) =13051820a(23) =28897016a(24) =63979205a(25) =141653762a(26) =313629217a(27) =694390210a(28) =1537413824a(29) =3403913006