Number of permutations of [n] that avoid the shuffle pattern s-k-t, where s = 1 and t = 123.
A324131
Number of permutations of [n] that avoid the shuffle pattern s-k-t, where s = 1 and t = 123.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =116a(6) =657a(7) =4260a(8) =31144a(9) =253400a(10) =2271250a(11) =22234380a(12) =236042879a(13) =2700973070a(14) =33139335352a(15) =433996381926
External references
- oeis: A324131