Ceiling(n/3)-perfect numbers.

Terms

a(0) =2a(1) =3a(2) =4a(3) =10a(4) =14a(5) =50a(6) =52a(7) =130a(8) =184a(9) =315a(10) =688a(11) =988a(12) =2528a(13) =6490a(14) =35456a(15) =396916a(16) =537088a(17) =538112a(18) =801376a(19) =1297312a(20) =8452096a(21) =8456192a(22) =35221184a(23) =53996590a(24) =134520832a(25) =222469702