Even square pyramidal numbers.

Terms

a(0) =14a(1) =30a(2) =140a(3) =204a(4) =506a(5) =650a(6) =1240a(7) =1496a(8) =2470a(9) =2870a(10) =4324a(11) =4900a(12) =6930a(13) =7714a(14) =10416a(15) =11440a(16) =14910a(17) =16206a(18) =20540a(19) =22140a(20) =27434a(21) =29370a(22) =35720a(23) =38024a(24) =45526a(25) =48230a(26) =56980a(27) =60116a(28) =70210a(29) =73810