OFFSET
1,1
COMMENTS
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
EXAMPLE
Table of n, a(n) for n = 1..12:
n a(n)
------------------------------------
1 144 = 12^2 = 2^4 * 3^2
2 324 = 18^2 = 2^2 * 3^4
3 576 = 24^2 = 2^6 * 3^2
4 1728 = 12^3 = 2^6 * 3^3
5 2304 = 48^2 = 2^8 * 3^2
6 2916 = 54^2 = 2^2 * 3^6
7 3600 = 60^2 = 2^4 * 3^2 * 5^2
8 5184 = 72^2 = 2^6 * 3^4
9 5832 = 18^3 = 2^3 * 3^6
10 8100 = 90^2 = 2^2 * 3^4 * 5^2
11 9216 = 96^2 = 2^10 * 3^2
12 11664 = 108^2 2^4 * 3^6
MATHEMATICA
nn = 360000; mm = Sqrt[nn]; i = 1; k = 2; fQ[x_] := And[#[[1, 1]] == 2, Length[#] > 1, CountDistinct[#[[;; , -1]] ] > 1, Union@ Differences@ Map[PrimePi, #[[;; , 1]] ] == {1}] &[FactorInteger[x]]; MapIndexed[Set[S[First[#2]], #1] &, Select[Range[mm], fQ]]; Union@ Reap[While[j = 2; While[S[i]^j < nn, Sow[S[i]^j]; j++]; j > 2, k++; i++] ][[-1, 1]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael De Vlieger, Oct 31 2025
STATUS
approved
