A088378 a(n) = (smallest prime factor of n)^3; a(1) = 1.

1, 8, 27, 8, 125, 8, 343, 8, 27, 8, 1331, 8, 2197, 8, 27, 8, 4913, 8, 6859, 8, 27, 8, 12167, 8, 125, 8, 27, 8, 24389, 8, 29791, 8, 27, 8, 125, 8, 50653, 8, 27, 8, 68921, 8, 79507, 8, 27, 8, 103823, 8, 343, 8, 27, 8, 148877, 8, 125, 8, 27, 8, 205379, 8, 226981

Offset: 1

Author

Reinhard Zumkeller, Sep 28 2003

Keywords

• nonn
• easy

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• Eric Weisstein's World of Mathematics, Cubic Number.
• Eric Weisstein's World of Mathematics, Least Prime Factor.

Crossrefs

Cf. A020639, A000578, A088377, A088379.

Programs

Mathematica

Table[FactorInteger[n][[1,1]]^3,{n,70}] (* Harvey P. Dale, Aug 05 2019 *)

PARI

a(n) = if(n == 1, 1, factor(n)[1,1]^3); \\ Amiram Eldar, May 16 2025

Formula

a(n) = A000578(A020639(n)).