Number of Dyck paths of semilength n having exactly 3 (possibly overlapping) occurrences of the consecutive steps UDUUUDDDUD (with U=(1,1), D=(1,-1)).
A243873
Number of Dyck paths of semilength n having exactly 3 (possibly overlapping) occurrences of the consecutive steps UDUUUDDDUD (with U=(1,1), D=(1,-1)).
Terms
- a(0) =1a(1) =5a(2) =23a(3) =105a(4) =472a(5) =2118a(6) =9446a(7) =41847a(8) =184256a(9) =806740a(10) =3514298a(11) =15238732a(12) =65803650a(13) =283077978a(14) =1213561196a(15) =5186141801a(16) =22098720181a(17) =93913940321a(18) =398127653185
External references
- oeis: A243873