The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #33 Mar 28 2016 08:07:08
%S 0,1,2,4,5,6,7,9,11,15,27
%N Nonnegative integers n such that n^3-3 is divisible by n-3.
%C Negative integers such that n^3-3 is divisible by n-3 are -1, -3, -5, -9 and -21.
%D W. Sierpiński, 250 Problems in Elementary Number Theory. New York: American Elsevier, Warsaw, 1970, Problem 2 page 1.
%e (7^3-3)/(7-3) = 85 so 7 is a term of this sequence.
%e (8^3-3)/(8-3) = 509/5 so 8 is not a term.
%t Select[Delete[Range@ 120, 3], Mod[#^3 - 3, # - 3] == 0 &] (* _Michael De Vlieger_, Aug 04 2015 *)
%o (PARI) lista(nn) = for (n=0, nn, if ((n!=3) && (Mod(n, n-3)^3 == Mod(3, n-3)), print1(n, ", "))); \\ _Michel Marcus_, Aug 04 2015
%K fini,full,nonn
%O 1,3
%A _Marco Ripà_, Jul 31 2015