a(n) = max_{k=0..n} k^(n-k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =9a(6) =27a(7) =81a(8) =256a(9) =1024a(10) =4096a(11) =16384a(12) =78125a(13) =390625a(14) =1953125a(15) =10077696a(16) =60466176a(17) =362797056a(18) =2176782336a(19) =13841287201a(20) =96889010407a(21) =678223072849