a(n) is the number of n nonintersecting arches above the x-axis that start and/or end with an arch length equal to one and have floor((n+2)/2) arches starting in odd numbered positions.
A298122
a(n) is the number of n nonintersecting arches above the x-axis that start and/or end with an arch length equal to one and have floor((n+2)/2) arches starting in odd numbered positions.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =11a(5) =34a(6) =90a(7) =300a(8) =875a(9) =3038a(10) =9408a(11) =33516a(12) =108108a(13) =392040a(14) =1302444a(15) =4785066a(16) =16256955a(17) =60324550a(18) =208579800a(19) =780088452a(20) =2735682092a(21) =10296854984a(22) =36532677272a(23) =138231751840a(24) =495241833996
External references
- oeis: A298122