Prime k with sigma(sigma(sigma(k))) < 3*k + 1.

Terms

a(0) =3a(1) =97a(2) =241a(3) =337a(4) =577a(5) =1249a(6) =3361a(7) =3697a(8) =4801a(9) =6961a(10) =8191a(11) =10657a(12) =14449a(13) =16561a(14) =18049a(15) =23761a(16) =25537a(17) =31249a(18) =32257a(19) =37537a(20) =48049a(21) =49297a(22) =64081a(23) =65521a(24) =77617a(25) =79201a(26) =89041a(27) =120049a(28) =126001a(29) =138337