a(n) = A126098(n) - 1.

Terms

a(0) =0a(1) =1a(2) =3a(3) =5a(4) =11a(5) =23a(6) =29a(7) =59a(8) =119a(9) =179a(10) =209a(11) =359a(12) =419a(13) =839a(14) =1259a(15) =1679a(16) =2519a(17) =4619a(18) =7559a(19) =9239a(20) =13859a(21) =18479a(22) =27719a(23) =55439a(24) =83159a(25) =110879a(26) =120119a(27) =180179a(28) =240239a(29) =360359