A179671 - OEIS

A179671

Products of the 5th power of a prime and a distinct prime of the 3rd power (p^5*q^3).

864, 1944, 4000, 10976, 25000, 30375, 42592, 70304, 83349, 84375, 134456, 157216, 219488, 323433, 389344, 453789, 533871, 780448, 953312, 1071875, 1193859, 1288408, 1620896, 1666737, 2100875, 2205472, 2544224, 2956581, 2970344, 3322336, 4159375, 4348377

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OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

Index to sequences related to prime signature

FORMULA

Sum_{n>=1} 1/a(n) = P(3)*P(5) - P(8) = A085541 * A085965 - A085968 = 0.002187..., where P is the prime zeta function. - Amiram Eldar, Jul 06 2020

MATHEMATICA

f[n_]:=Sort[Last/@FactorInteger[n]]=={3, 5}; Select[Range[10^6], f]

CROSSREFS

Cf. A085541, A085965, A085968.