Problimes (second definition).

Terms

a(0) =2a(1) =4a(2) =7a(3) =10a(4) =13a(5) =17a(6) =21a(7) =25a(8) =29a(9) =34a(10) =39a(11) =44a(12) =49a(13) =54a(14) =59a(15) =64a(16) =69a(17) =74a(18) =79a(19) =84a(20) =90a(21) =96a(22) =102a(23) =108a(24) =114a(25) =120a(26) =126a(27) =132a(28) =138a(29) =144