a(n) = sum of the numbers between the two n's in A026346.

Terms

a(0) =0a(1) =7a(2) =17a(3) =23a(4) =47a(5) =69a(6) =107a(7) =153a(8) =171a(9) =211a(10) =274a(11) =298a(12) =372a(13) =430a(14) =460a(15) =551a(16) =621a(17) =657a(18) =765a(19) =881a(20) =969a(21) =1099a(22) =1147a(23) =1247a(24) =1394a(25) =1549a(26) =1606a(27) =1724a(28) =1896a(29) =1959