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={0}.

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =6a(5) =11a(6) =23a(7) =51a(8) =113a(9) =244a(10) =526a(11) =1142a(12) =2483a(13) =5389a(14) =11687a(15) =25358a(16) =55034a(17) =119430a(18) =259151a(19) =562340a(20) =1220276a(21) =2647993a(22) =5746085a(23) =12468857a(24) =27057165a(25) =58713537a(26) =127407187a(27) =276470942a(28) =599936262a(29) =1301849496