Number of Dyck paths of semilength n having exactly three (possibly overlapping) occurrences of the consecutive step pattern UDU, where U = (1,1) and D = (1,-1).
A371408
Number of Dyck paths of semilength n having exactly three (possibly overlapping) occurrences of the consecutive step pattern UDU, where U = (1,1) and D = (1,-1).
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =4a(6) =20a(7) =80a(8) =315a(9) =1176a(10) =4284a(11) =15240a(12) =53295a(13) =183700a(14) =625768a(15) =2110472a(16) =7057505a(17) =23427600a(18) =77271120a(19) =253426752a(20) =827009523a(21) =2686728060a(22) =8693388060a(23) =28026897360a(24) =90058925649a(25) =288516259416a(26) =921755412900
External references
- oeis: A371408