OFFSET
1,1
LINKS
Robert Price, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
A190641(4) = 12, 12 = 2*2*3, so 12 has only one square factor, namely 4, and the square root is 2.
MATHEMATICA
f[n_] := Module[{f = FactorInteger[n], ind}, ind = Position[f[[;; , 2]], _?(# > 1 &)]; If[Length[ind] == 1, f[[ind[[1, 1]], 1]], Nothing]]; Array[f, 300] (* Amiram Eldar, Jul 28 2024 *)
PROG
(PARI) lista(kmax) = for(k = 1, kmax, my(f = factor(k)); if(#select(x -> (x>1), f[, 2]) == 1, for(i = 1, #f~, if(f[i, 2] > 1, print1(f[i, 1], ", "); break)))); \\ Amiram Eldar, Jul 28 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert Price, Mar 13 2017
STATUS
approved