Number of permutations of length n containing exactly 2 occurrences of 1234 and 2 occurrences of 1243.
A224294
Number of permutations of length n containing exactly 2 occurrences of 1234 and 2 occurrences of 1243.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =2a(6) =34a(7) =382a(8) =3518a(9) =28708a(10) =216098a(11) =1536960a(12) =10488708a(13) =69393216a(14) =448301130a(15) =2842611306a(16) =17758399872a(17) =109613418746a(18) =669950441982
External references
- oeis: A224294