Convolution of A015723 and A000700.

Terms

a(0) =0a(1) =1a(2) =2a(3) =4a(4) =7a(5) =10a(6) =18a(7) =26a(8) =36a(9) =53a(10) =76a(11) =104a(12) =140a(13) =190a(14) =252a(15) =336a(16) =437a(17) =564a(18) =732a(19) =936a(20) =1186a(21) =1504a(22) =1894a(23) =2366a(24) =2950a(25) =3659a(26) =4520a(27) =5564a(28) =6822a(29) =8330