OFFSET
1,1
COMMENTS
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
Let b(n) = A126706(n).
a(1) = b(1)^2 = 12^2 = 144. Since 144 = 2^4*3^2, it is both powerful and a perfect power.
a(2) = b(2)^2 = 18^2 = 324.
a(3) = b(3)^2 = 20^2 = 400.
a(8) = b(1)^3 = 12^3 = 1728, etc.
MATHEMATICA
nn = 20000; i = 1; k = 2;
MapIndexed[Set[S[First[#2]], #1] &,
Select[Range@ Sqrt[nn], Nor[SquareFreeQ[#], PrimePowerQ[#]] &] ];
Union@ Reap[
While[j = 2;
While[S[i]^j < nn, Sow[S[i]^j]; j++]; j > 2,
k++; i++] ][[-1, 1]]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Michael De Vlieger, Jan 01 2024
STATUS
approved