Inverse Euler transform of A003480.

Terms

a(0) =1a(1) =2a(2) =4a(3) =12a(4) =31a(5) =92a(6) =256a(7) =772a(8) =2291a(9) =7000a(10) =21476a(11) =66804a(12) =208935a(13) =658924a(14) =2088628a(15) =6656820a(16) =21306270a(17) =68468796a(18) =220776444a(19) =714117012a(20) =2316229821a(21) =7531561676a(22) =24545492916a(23) =80160031076a(24) =262279882239a(25) =859660694960