a(n) = Sum_{m=1..n} (Sum_{k=1..m} (Sum_{j=1..k} j^k)).

A349117

a(n) = Sum_{m=1..n} (Sum_{k=1..m} (Sum_{j=1..k} j^k)).

Terms

    a(0) =1a(1) =7a(2) =49a(3) =445a(4) =5266a(5) =77258a(6) =1349554a(7) =27306462a(8) =627568355a(9) =16142172173a(10) =459332766227

External references