OFFSET
1,1
COMMENTS
Lacampagne and Selfridge proved that these are the only terms.
The positions of the terms in A005934 are 2, 8, 10, 25, 27, 28, 30, 33, 55, 58, 60, 62, 107, 161, 230, 234, 240, 302, 315.
LINKS
Carole B. Lacampagne and John L. Selfridge, Large highly powerful numbers are cubeful, Proceedings of the American Mathematical Society, Vol. 91, No. 2 (1984), pp. 173-181.
MATHEMATICA
pmax = 1; s = {}; Do[e = FactorInteger[n][[;; , 2]]; p = Times @@ e; If[p > pmax, pmax = p; If[Min[e] < 3, AppendTo[s, n]]], {n, 2, 10^6}]; s
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
Amiram Eldar, Apr 22 2019
STATUS
approved