Numbers n such that Sum_{i=1..j} 1/pn(i) + Sum_{i=1..k} 1/pd(i) is an integer, where pn are the prime factors of n and pd the prime factors of the arithmetic derivative of n, both counted with multiplicity.
A239490
Numbers n such that Sum_{i=1..j} 1/pn(i) + Sum_{i=1..k} 1/pd(i) is an integer, where pn are the prime factors of n and pd the prime factors of the arithmetic derivative of n, both counted with multiplicity.
Terms
- a(0) =4a(1) =27a(2) =256a(3) =1728a(4) =2401a(5) =3125a(6) =11664a(7) =72000a(8) =78732a(9) =200000a(10) =486000a(11) =531441a(12) =823543a(13) =1350000a(14) =3280500a(15) =9112500a(16) =22143375a(17) =52706752a(18) =56250000a(19) =61509375a(20) =156250000
External references
- oeis: A239490