The Jacobsthal sequence is named after the German mathematician Ernst Jacobsthal. It is formed with the formula
The first numbers are
0,
1,
1,
3,
5,
11,
21,
43,
85,
171,
341,
683,
1365,
2731,
5461,
10923,
21845,
43691,
87381,
174763,
349525,
699051,
1398101,
2796203,
5592405,
11184811,
22369621,
44739243,
89478485,
178956971,
357913941,
715827883,
1431655765,
2863311531,
5726623061