Numbers n such that sigma(n) - n = {number of primes <= n}.
A037172
Numbers n such that sigma(n) - n = {number of primes <= n}.
Terms
- a(0) =1a(1) =2a(2) =9a(3) =85a(4) =2569a(5) =2723a(6) =2807a(7) =174449a(8) =1302379a(9) =8513821a(10) =10518107a(11) =14348051a(12) =70110091a(13) =70111621a(14) =70112369a(15) =10910880311a(16) =43908943297
External references
- oeis: A037172