Number of up steps starting at an odd level in all nondecreasing Dyck paths of semilength n. A nondecreasing Dyck path is a Dyck path for which the sequence of the altitudes of the valleys is nondecreasing.
A121525
Number of up steps starting at an odd level in all nondecreasing Dyck paths of semilength n. A nondecreasing Dyck path is a Dyck path for which the sequence of the altitudes of the valleys is nondecreasing.
Terms
- a(0) =0a(1) =1a(2) =5a(3) =19a(4) =67a(5) =219a(6) =690a(7) =2110a(8) =6322a(9) =18639a(10) =54268a(11) =156398a(12) =446960a(13) =1268351a(14) =3577679a(15) =10039583a(16) =28046201a(17) =78039545a(18) =216388938a(19) =598136340a(20) =1648730940a(21) =4533180211a(22) =12435470410a(23) =34042090044a(24) =93012717072a(25) =253692955789
External references
- oeis: A121525