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 A144854 #8 Aug 01 2015 12:10:08 %S A144854 25,99,609,650,1189,3479,4901,5429,11659,16275,29469,38479,62525, %T A144854 73814,78089,117739,142449,201116,203319,240199,328769,381275,406900, %U A144854 504889,576909,743775,839629,1005731,1058819,1183259,1464709,1622919,1960244 %N A144854 Values of n such that the expression sqrt(4!*(n+1) + 1) yields a perfect power. %e A144854 25 is in the sequence since sqrt(4!*(25+1) + 1) = 25 = 5^2; %e A144854 99 is in the sequence since sqrt(4!*(99+1) + 1) = 49 = 7^2. - _Jon E. Schoenfield_, Aug 01 2015 %t A144854 lst = {}; Do[a = Sqrt[4! (n + 1) + 1]; If[IntegerQ@ a && GCD @@ Last /@ FactorInteger@a > 1, AppendTo[lst, n]], {n, 0, 1977428}]; lst (* _Robert G. Wilson v_, Sep 24 2008 *) %Y A144854 Subset of A144065. %K A144854 nonn %O A144854 1,1 %A A144854 _Alexander R. Povolotsky_, Sep 22 2008 %E A144854 More terms from _Robert G. Wilson v_, Sep 24 2008