Numbers n such that Sum_{i=1..j} 1/d(i) - Sum_{i=1..k} 1/p(i) is an integer, where p are the prime factors of n, counted with multiplicity, and d its divisors.
A238922
Numbers n such that Sum_{i=1..j} 1/d(i) - Sum_{i=1..k} 1/p(i) is an integer, where p are the prime factors of n, counted with multiplicity, and d its divisors.
Terms
- a(0) =1a(1) =12a(2) =18a(3) =220a(4) =396a(5) =17296a(6) =24016a(7) =287532a(8) =4661056a(9) =64288512a(10) =334144656a(11) =358585488a(12) =555192576a(13) =568719616a(14) =2172649216a(15) =2451538112a(16) =2645953344a(17) =2955423888a(18) =6704333824a(19) =26996772032a(20) =88734733632a(21) =147861504000a(22) =311063879024a(23) =371226582848a(24) =429391876096
External references
- oeis: A238922