a(n) = Sum_{k=1..n} A123706(n,k)*2^(k-1).

Terms

a(0) =1a(1) =0a(2) =1a(3) =3a(4) =7a(5) =14a(6) =31a(7) =60a(8) =126a(9) =248a(10) =511a(11) =1005a(12) =2047a(13) =4064a(14) =8183a(15) =16320a(16) =32767a(17) =65394a(18) =131071a(19) =261885a(20) =524255a(21) =1048064a(22) =2097151a(23) =4193220a(24) =8388600a(25) =16775168a(26) =33554304a(27) =67104765a(28) =134217727a(29) =268427002