A369430 Smallest number whose square is divisible by the n-th powerful number.
1, 2, 4, 3, 4, 5, 9, 8, 6, 7, 8, 12, 9, 10, 18, 11, 25, 16, 12, 13, 14, 20, 36, 15, 27, 16, 24, 17, 18, 49, 19, 28, 20, 36, 21, 22, 50, 32, 23, 24, 25, 36, 45, 26, 27, 28, 40, 29, 72, 30, 31, 44, 54, 100, 32, 33, 75, 48, 34, 35, 36, 63, 121, 52, 37, 98, 38, 39
Offset: 1
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
-
Mathematica
f[p_, e_] := p^Ceiling[e/2]; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; s /@ Select[Range[2000], # == 1 || Min[FactorInteger[#][[;; , 2]]] > 1 &] (* or *) f[p_, e_] := p^Ceiling[e/2]; f[p_, 1] := 0; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; Select[Array[s, 2000], # > 0 &]
-
PARI
s(n) = {my(f = factor(n)); prod(i = 1, #f~, if(f[i,2] == 1, 0, f[i,1]^ceil(f[i,2]/2)));} lista(kmax) = {my(s1); for(k = 1, kmax, s1 = s(k); if(s1 > 0, print1(s1, ", ")));}