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 A364277 #13 Jul 23 2023 17:02:34 %S A364277 1,0,0,1,4,24,138,1032,8160,75600,751680,8436960,100679040,1327052160, %T A364277 18525024000,280451808000,4477627123200,76690072166400, %U A364277 1377634946688000,26328977260185600,525869478021888000,11092929741653760000,243781091314016256000,5628622656645660672000 %N A364277 Number of permutations of [n] such that no cycle contains its length as an element. %H A364277 Wikipedia, <a href="https://en.wikipedia.org/wiki/Permutation">Permutation</a> %e A364277 a(3) = 1: (13)(2). %e A364277 a(4) = 4: (124)(3), (142)(3), (13)(2)(4), (14)(2)(3). %Y A364277 Cf. A362362, A363881, A364279, A364406. %K A364277 nonn %O A364277 0,5 %A A364277 _Alois P. Heinz_, Jul 17 2023