OFFSET
1,1
LINKS
Hieronymus Fischer, Table of n, a(n) for n = 1..300
EXAMPLE
a(3)=693, since 693=3*3*7*11 and (2*3^3+7^3+11^3)^(1/3)=1728^(1/3)=12.
MATHEMATICA
criQ[n_]:=IntegerQ[Surd[Total[Flatten[Table[#[[1]], #[[2]]]&/@ FactorInteger[ n]]^3], 3]]; Select[Range[1670000], CompositeQ[#] && criQ[#]&] (* Harvey P. Dale, Sep 19 2021 *)
PROG
(PARI) lista(m) = {for (i=2, m, if (! isprime(i), f = factor(i); s = sum (j=1, length(f~), f[j, 1]^3*f[j, 2]); if (ispower(s, 3), print1(i, ", ")); ); ); } \\ Michel Marcus, Apr 14 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Hieronymus Fischer, Nov 11 2007
EXTENSIONS
Minor edits by Hieronymus Fischer, Apr 20 2013
STATUS
approved