a(1) = 1, otherwise a(n) = floor(Pi^(n+1)/(Pi^2 + 1)).

Terms

a(0) =0a(1) =1a(2) =2a(3) =8a(4) =28a(5) =88a(6) =277a(7) =872a(8) =2742a(9) =8615a(10) =27066a(11) =85032a(12) =267137a(13) =839236a(14) =2636539a(15) =8282934a(16) =26021606a(17) =81749286a(18) =256822957a(19) =806833116a(20) =2534740992a(21) =7963123679a(22) =25016890850a(23) =78592880512a(24) =246906816042a(25) =775680639401