a(n) = Sum_{k=0..n} C(n*(n+1)/2,k).
A066383
a(n) = Sum_{k=0..n} C(n*(n+1)/2,k).
Terms
- a(0) =1a(1) =2a(2) =7a(3) =42a(4) =386a(5) =4944a(6) =82160a(7) =1683218a(8) =40999516a(9) =1156626990a(10) =37060382822
External references
- oeis: A066383
A066383
a(n) = Sum_{k=0..n} C(n*(n+1)/2,k).