First differences of A130624.

Terms

a(0) =1a(1) =4a(2) =7a(3) =11a(4) =20a(5) =41a(6) =85a(7) =172a(8) =343a(9) =683a(10) =1364a(11) =2729a(12) =5461a(13) =10924a(14) =21847a(15) =43691a(16) =87380a(17) =174761a(18) =349525a(19) =699052a(20) =1398103a(21) =2796203a(22) =5592404a(23) =11184809a(24) =22369621a(25) =44739244a(26) =89478487a(27) =178956971a(28) =357913940a(29) =715827881