a(n) is smallest number which is uniquely of the form a(j) + a(k) with 1 <= j < k < n and a(1) = 1, a(2) = 4.

A003666

a(n) is smallest number which is uniquely of the form a(j) + a(k) with 1 <= j < k < n and a(1) = 1, a(2) = 4.

Terms

    a(0) =1a(1) =4a(2) =5a(3) =6a(4) =7a(5) =8a(6) =10a(7) =16a(8) =18a(9) =19a(10) =21a(11) =31a(12) =32a(13) =33a(14) =42a(15) =46a(16) =56a(17) =57a(18) =66a(19) =70a(20) =79a(21) =82a(22) =91a(23) =96a(24) =104a(25) =105a(26) =107a(27) =116a(28) =129a(29) =130

External references