a(n) = Sum_{k=0..n} Stirling2(n,k) * binomial(3*k,k) / (2*k + 1).
A346764
a(n) = Sum_{k=0..n} Stirling2(n,k) * binomial(3*k,k) / (2*k + 1).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =22a(4) =149a(5) =1169a(6) =10272a(7) =99012a(8) =1032346a(9) =11526094a(10) =136755650a(11) =1714031312a(12) =22584475206a(13) =311597054110
External references
- oeis: A346764