a(n) = Sum_{j=0..n} A000293(j).

Terms

a(0) =1a(1) =2a(2) =6a(3) =16a(4) =42a(5) =101a(6) =241a(7) =548a(8) =1232a(9) =2696a(10) =5818a(11) =12318a(12) =25744a(13) =52992a(14) =107796a(15) =216598a(16) =430669a(17) =847518a(18) =1652642a(19) =3194279a(20) =6124608a(21) =11653341a(22) =22015653a(23) =41310879a(24) =77024333a(25) =142739427a(26) =262996080a(27) =481889660a(28) =878308359a(29) =1592707740