Lesser of twin primes p >= 3 for which sigma(p+1)/sigma(p-1) reaches record value, where sigma(n) is the divisor sum function (A000203).
A326391
Lesser of twin primes p >= 3 for which sigma(p+1)/sigma(p-1) reaches record value, where sigma(n) is the divisor sum function (A000203).
Terms
- a(0) =3a(1) =7559a(2) =42839a(3) =55439a(4) =110879a(5) =415799a(6) =1713599a(7) =1940399a(8) =2489759a(9) =6652799a(10) =6846839a(11) =15855839a(12) =31600799a(13) =85765679a(14) =232792559a(15) =845404559a(16) =1470268799a(17) =6299092799a(18) =10708457759a(19) =17459441999a(20) =32125373279a(21) =135019684799a(22) =439977938399a(23) =449755225919
External references
- oeis: A326391