A303544 Numbers k that divide primepi(k)^prime(k).

1, 4, 8, 16, 27, 64, 96, 120, 125, 169, 189, 256, 324, 350, 605, 729, 864, 896, 1008, 1024, 1080, 1116, 1296, 1375, 1444, 2187, 2209, 2268, 2304, 2349, 2401, 2430, 2888, 3087, 3125, 3328, 3645, 3698, 4000, 4096, 4356, 4394, 5184, 6480, 8192, 8464, 10648

Offset

1,2

Comments

Except for 1, terms are not squarefree, that is, all terms > 1 form a subsequence of A013929.

Links

Chai Wah Wu, Table of n, a(n) for n = 1..500

Formula

Numbers k such that the set of prime factors of k is a subset of the set of prime factors of primepi(k).

Mathematica

Select[Range[2^14], PowerMod[PrimePi[#], Prime[#], #] == 0 &] (* Michael De Vlieger, May 14 2018 *)

Prog

(PARI) isok(n) = !(primepi(n)^prime(n) % n); \\ Michel Marcus, May 14 2018

Crossrefs

Cf. A013929, A109710.

Sequence in context: A368985 A334198 A358730 * A273029 A273080 A020193

Adjacent sequences: A303541 A303542 A303543 * A303545 A303546 A303547

Keyword

nonn

Author

Chai Wah Wu, Apr 25 2018

Status

approved