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={-1,2}.
A080004
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={-1,2}.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =9a(6) =15a(7) =25a(8) =46a(9) =84a(10) =156a(11) =280a(12) =501a(13) =909a(14) =1647a(15) =2990a(16) =5408a(17) =9773a(18) =17695a(19) =32033a(20) =58000a(21) =104976a(22) =189968a(23) =343860a(24) =622409a(25) =1126617a(26) =2039201a(27) =3690898a(28) =6680644a(29) =12092173
External references
- oeis: A080004