Primes p such that (p-1)/2 and p+1 have the same sum of divisors.

Terms

a(0) =24001a(1) =95881a(2) =205633a(3) =2266177a(4) =3792673a(5) =3850393a(6) =6846241a(7) =7448641a(8) =15498121a(9) =21566497a(10) =25267681a(11) =28987681a(12) =48114841a(13) =57207697a(14) =69805261a(15) =79176001a(16) =90257521a(17) =110360641a(18) =121223761a(19) =129642001a(20) =139752001a(21) =164655793a(22) =166175461a(23) =185983981a(24) =211268881a(25) =264159601