This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A152219 #9 Jun 10 2025 01:37:23
%S A152219 9,15,105,112,609,4929
%N A152219 Numbers k such that k! - 1 is divisible by a square greater than one.
%C A152219 Primes p such that p^2 divides m!-1 for some integer m<p see A152220.
%t A152219 aa = {}; Do[If[(Sqrt[n! - 1] /. Sqrt[_] -> 1) > 1, Print[n]; AppendTo[aa, n]], {n, 1, 1000}]; aa
%t A152219 (* alternate program *)
%t A152219 nfdsQ[n_]:=AnyTrue[Rest[Divisors[n!-1]],IntegerQ[Sqrt[#]]&]; Select[Range[ 2,610],nfdsQ] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, May 24 2020 *)
%Y A152219 Cf. A064237.
%K A152219 nonn,more
%O A152219 1,1
%A A152219 _Artur Jasinski_, Nov 29 2008
%E A152219 a(6) from _Artur Jasinski_, Nov 30 2008
%E A152219 Definition clarified by _Harvey P. Dale_, May 24 2020