Central column of arrays in A057027 and A057028.

Terms

a(0) =1a(1) =6a(2) =12a(3) =27a(4) =39a(5) =64a(6) =82a(7) =117a(8) =141a(9) =186a(10) =216a(11) =271a(12) =307a(13) =372a(14) =414a(15) =489a(16) =537a(17) =622a(18) =676a(19) =771a(20) =831a(21) =936a(22) =1002a(23) =1117a(24) =1189a(25) =1314a(26) =1392a(27) =1527a(28) =1611a(29) =1756