Numbers k such that sigma(prime(k) - 1) == 0 (mod k).

Terms

a(0) =1a(1) =4a(2) =9a(3) =27a(4) =42a(5) =60a(6) =64a(7) =70a(8) =78a(9) =144a(10) =168a(11) =180a(12) =216a(13) =238a(14) =260a(15) =318a(16) =558a(17) =600a(18) =672a(19) =960a(20) =1008a(21) =1053a(22) =1260a(23) =1620a(24) =1806a(25) =2112a(26) =3318a(27) =3780a(28) =4608a(29) =5544