Irregular primes with irregularity index four.

Terms

a(0) =12613a(1) =15737a(2) =43189a(3) =56263a(4) =72337a(5) =76289a(6) =77783a(7) =84067a(8) =102559a(9) =108179a(10) =109789a(11) =109843a(12) =109891a(13) =115727a(14) =115901a(15) =120557a(16) =125927a(17) =127247a(18) =135613a(19) =149287a(20) =155599a(21) =161461a(22) =169843a(23) =172973a(24) =178307a(25) =179233a(26) =184559a(27) =188519a(28) =192271a(29) =198461