a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/3)} binomial(n,3*k+1) * a(n-3*k-1).
A352428
a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/3)} binomial(n,3*k+1) * a(n-3*k-1).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =25a(5) =130a(6) =810a(7) =5881a(8) =48806a(9) =455706a(10) =4727881a(11) =53955682a(12) =671730246a(13) =9059714665a(14) =131588822822
External references
- oeis: A352428