Triangle read by rows: row n lists prime factors of (p^p-1)/(p-1) where p = prime(n).

Terms

a(0) =3a(1) =13a(2) =11a(3) =71a(4) =29a(5) =4733a(6) =15797a(7) =1806113a(8) =53a(9) =264031a(10) =1803647a(11) =10949a(12) =1749233a(13) =2699538733a(15) =461a(16) =1289a(17) =831603031789a(19) =59a(20) =16763a(21) =84449a(22) =2428577a(23) =14111459a(24) =58320973a(25) =549334763a(27) =149a(28) =1999a(29) =7993a(30) =16651a(31) =17317