a(2*n) = n*a(n); a(2*n+1) = n*a(n) + a(n+1), with a(1) = 1.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =4a(5) =6a(6) =8a(7) =8a(8) =12a(9) =20a(10) =26a(11) =36a(12) =44a(13) =56a(14) =64a(15) =64a(16) =76a(17) =108a(18) =128a(19) =200a(20) =226a(21) =286a(22) =322a(23) =432a(24) =476a(25) =572a(26) =628a(27) =784a(28) =848a(29) =960