a(n) = floor(Pi^n/n^Pi).

Terms

a(0) =3a(1) =1a(2) =0a(3) =1a(4) =1a(5) =3a(6) =6a(7) =13a(8) =29a(9) =67a(10) =157a(11) =376a(12) =919a(13) =2287a(14) =5786a(15) =14843a(16) =38545a(17) =101191a(18) =268240a(19) =717284a(20) =1933182a(21) =5247494a(22) =14336822a(23) =39403558a(24) =108890190a(25) =302431354a(26) =843887738a(27) =2364914235a(28) =6654072084a(29) =18792428153