Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={0}.

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =9a(5) =24a(6) =57a(7) =140a(8) =376a(9) =1016a(10) =2692a(11) =7020a(12) =18369a(13) =48344a(14) =127465a(15) =335510a(16) =882081a(17) =2319136a(18) =6100393a(19) =16049440a(20) =42220168a(21) =111053856a(22) =292109320a(23) =768373144a(24) =2021186393a(25) =5316647448a(26) =13985104873a(27) =36786882378a(28) =96765680857a(29) =254536684328