Binomial coefficients: C(n,k), 2 <= k <= n-2, sorted, duplicates removed.

Terms

a(0) =6a(1) =10a(2) =15a(3) =20a(4) =21a(5) =28a(6) =35a(7) =36a(8) =45a(9) =55a(10) =56a(11) =66a(12) =70a(13) =78a(14) =84a(15) =91a(16) =105a(17) =120a(18) =126a(19) =136a(20) =153a(21) =165a(22) =171a(23) =190a(24) =210a(25) =220a(26) =231a(27) =252a(28) =253a(29) =276