a(n) = sum of the numbers between the two n's in A026338.

Terms

a(0) =0a(1) =3a(2) =6a(3) =14a(4) =25a(5) =24a(6) =38a(7) =48a(8) =75a(9) =89a(10) =114a(11) =142a(12) =141a(13) =160a(14) =193a(15) =229a(16) =228a(17) =267a(18) =293a(19) =354a(20) =402a(21) =434a(22) =487a(23) =486a(24) =602a(25) =601a(26) =663a(27) =728a(28) =771a(29) =770