Number of permutations of length n which avoid the patterns 3421, 4123, 4312; or avoid the patterns 2341, 3142, 3214.
A116837
Number of permutations of length n which avoid the patterns 3421, 4123, 4312; or avoid the patterns 2341, 3142, 3214.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =21a(4) =73a(5) =250a(6) =853a(7) =2911a(8) =9938a(9) =33931a(10) =115849a(11) =395534a(12) =1350437a(13) =4610679a(14) =15741842a(15) =53746011a(16) =183500361a(17) =626509422a(18) =2139036965a(19) =7303129015a(20) =24934442130a(21) =85131510491a(22) =290657157705a(23) =992365609838
External references
- oeis: A116837