Primes p such that sigma(p+1) = sigma(p-1).

Terms

a(0) =367a(1) =919a(2) =30593a(3) =95393a(4) =117571a(5) =124759a(6) =147341a(7) =197261a(8) =334541a(9) =344417a(10) =463219a(11) =732257a(12) =755081a(13) =931757a(14) =982759a(15) =1996759a(16) =2401219a(17) =2962697a(18) =3013447a(19) =4722941a(20) =7892827a(21) =13333097a(22) =13358407a(23) =17946259a(24) =19828483a(25) =19855471a(26) =19904981