A367103 Composite numbers c such that pi(c) is the product of pi applied to the distinct prime factors of c.

15, 21, 39, 57, 65, 91, 95, 133

Offset

1,1

Comments

Prime numbers trivially satisfy this property and so are excluded.

Links

Table of n, a(n) for n=1..8.

Example

15 is a term since its distinct prime factors are 3,5 and pi(15) = pi(3)*pi(5).

Mathematica

Select[Range[2, 10000], ! PrimeQ[#] && Times @@ PrimePi[Transpose[FactorInteger[#]][[1]]] == PrimePi[#] &]

Crossrefs

Cf. A000720, A002808, A027748, A156061, A235623.

Sequence in context: A335674 A349096 A063175 * A325658 A331628 A171569

Adjacent sequences: A367100 A367101 A367102 * A367104 A367105 A367106

Keyword

nonn,fini,full

Author

Tanya Khovanova, Nov 04 2023

Status

approved