Partial sums of Jacobsthal gap sequence.

Terms

a(0) =0a(1) =1a(2) =4a(3) =5a(4) =20a(5) =21a(6) =84a(7) =85a(8) =340a(9) =341a(10) =1364a(11) =1365a(12) =5460a(13) =5461a(14) =21844a(15) =21845a(16) =87380a(17) =87381a(18) =349524a(19) =349525a(20) =1398100a(21) =1398101a(22) =5592404a(23) =5592405a(24) =22369620a(25) =22369621a(26) =89478484a(27) =89478485a(28) =357913940a(29) =357913941