a(n) = ceiling(n^(1/n))^n - n.

Terms

a(0) =0a(1) =2a(2) =5a(3) =12a(4) =27a(5) =58a(6) =121a(7) =248a(8) =503a(9) =1014a(10) =2037a(11) =4084a(12) =8179a(13) =16370a(14) =32753a(15) =65520a(16) =131055a(17) =262126a(18) =524269a(19) =1048556a(20) =2097131a(21) =4194282a(22) =8388585a(23) =16777192a(24) =33554407a(25) =67108838a(26) =134217701a(27) =268435428a(28) =536870883a(29) =1073741794