A086132 - OEIS

%I #17 Jul 12 2024 10:16:38

%S 4,9,16,25,27,49,50,54,81,108,121,125,144,169,196,225,242,256,289,343,

%T 361,392,400,432,441,500,529,578,605,625,676,729,784,841,847,961,972,

%U 1014,1029,1058,1083,1089,1183,1225,1323,1331,1369,1372,1444,1445,1452

%N Numbers that have the same largest prime factor as their arithmetic derivative.

%H Amiram Eldar, <a href="/A086132/b086132.txt">Table of n, a(n) for n = 1..10000</a>

%t q[n_] := Module[{f = FactorInteger[n]}, FactorInteger[n * Plus @@ ((Last[#] / First[#]) & /@ f)][[-1, 1]] == f[[-1, 1]]]; Select[Range[2, 1500], q] (* _Amiram Eldar_, Jul 12 2024 *)

%Y Cf. A003415, A006530.

%K nonn

%O 1,1

%A _Labos Elemer_, Jul 23 2003