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 A260373 #18 May 22 2025 10:21:43 %S A260373 1,1,1,4,25,121,729,5041,40401,362404,3629025,39917124,478996996, %T A260373 6226945921,87178467600,1307674583296,20922793332736,355687416544329, %U A260373 6402373660047556,121645100663836929,2432902009335560361,51090942169052381124,1124000727752683686724 %N A260373 The nearest perfect square to n! %C A260373 a(n) is well defined as the squares are alternatingly odd and even and thus the average of two successive squares is not an integer and thus no integer is equidistant to two successive squares. - _Chai Wah Wu_, Jul 24 2015 %F A260373 a(n) = A055227(n)^2. %e A260373 6! = 720. The nearest perfect square is 729. %o A260373 (PARI) a(n)=round(sqrt(n!))^2 \\ _Charles R Greathouse IV_, Jul 23 2015 %o A260373 (Python) %o A260373 from gmpy2 import isqrt %o A260373 A260373_list, g = [1], 1 %o A260373 for i in range(1, 101): %o A260373 g *= i %o A260373 s = isqrt(g) %o A260373 t = s**2 %o A260373 A260373_list.append(int(t if g-t-s <= 0 else t+2*s+1)) # _Chai Wah Wu_, Jul 23 2015 %Y A260373 Cf. A055227, A260374. %K A260373 nonn,easy %O A260373 0,4 %A A260373 _Otis Tweneboah_, _Pratik Koirala_, _Eugene Fiorini_, _Nathan Fox_, Jul 23 2015