First differences of A112877 (zero terms in Cald's sequence A006509).

Terms

a(0) =82a(1) =182a(2) =46a(3) =94a(4) =200a(5) =430a(6) =846a(7) =1628a(8) =2982a(9) =5662a(10) =10940a(11) =17924a(12) =34308a(13) =65768a(14) =125760a(15) =240732a(16) =460672a(17) =883598a(18) =1697502a(19) =3268008a(20) =6297778a(21) =12152690a(22) =23482980a(23) =45422208a(24) =87949242a(25) =170465380a(26) =330760622a(27) =642315104a(28) =1094147916a(29) =2132023868