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 A140393 #23 Jan 31 2025 05:49:18 %S A140393 1,0,0,2,10,4,40,92,352,724,2680,14200,73712,365596,2279184,14772512, %T A140393 95815104,666090624,4968057848,39029188884,314666222712,2691008701644, %U A140393 24233937684440,226732487925864 %N A140393 Erroneous duplicate of A000170, see comments. %C A140393 This is a new calculation of A000170 which produced a different answer for n=24. I do not know which version is correct and I have therefore created this second entry for the values found by the NQueens(AT)home team. See the main entry for this sequence, A000170, for many further references and comments. %C A140393 As discovered on Nov 07 2008, this sequence is likely to suffer from an overflow error in the implementation of the NQueens(AT)Home project. The results differ by 781684047872 = 0xb600000000 = 182 * 2^32. %H A140393 NQueens(AT)home, <a href="https://web.archive.org/web/20090926014014/http://nqueens.ing.udec.cl:80/">Home Page</a> [Via Internet Archive Wayback-Machine] %Y A140393 See A000170 for further information. %K A140393 dead %O A140393 1,4 %A A140393 _N. J. A. Sloane_, Jun 18 2008 %E A140393 a(24) is probably mistaken. - _Thomas B. Preußer_, Nov 07 2008