Number at end of segment n of A078783.

Terms

a(0) =6a(1) =13a(2) =25a(3) =48a(4) =91a(5) =176a(6) =345a(7) =682a(8) =1355a(9) =2698a(10) =5383a(11) =10752a(12) =21489a(13) =42962a(14) =85907a(15) =171796a(16) =343573a(17) =687126a(18) =1374231a(19) =2748438a(20) =5496851a(21) =10993676a(22) =21987325a(23) =43974622a(24) =87949215a(25) =175898400a(26) =351796769a(27) =703593506a(28) =1407186979a(29) =2814373924