Triangle read by rows: row n lists divisors of n-th perfect number A000396(n).

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =1a(5) =2a(6) =4a(7) =7a(8) =14a(9) =28a(10) =1a(11) =2a(12) =4a(13) =8a(14) =16a(15) =31a(16) =62a(17) =124a(18) =248a(19) =496a(20) =1a(21) =2a(22) =4a(23) =8a(24) =16a(25) =32a(26) =64a(27) =127a(28) =254a(29) =508