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 A381243 #12 May 17 2025 10:16:44 %S A381243 0,0,1,6,85,1370,30481,778610,24409645,881325366,36635553601, %T A381243 1713454403210,89415912126223,5143372266050837,323667807885619744, %U A381243 22112062644980805684 %N A381243 Number of hyperplanes defined by the nonzero differences of two permutations of order n. %C A381243 Each of A175176(n) - 1 nonzero differences between two permutations (viewed as vectors) defines a hyperplane in the n-dimensional space. a(n) gives the number of pairwise distinct hyperplanes among them. %Y A381243 Cf. A019589, A175176, A362968, A381244, A381339. %K A381243 nonn,more %O A381243 0,4 %A A381243 _Max Alekseyev_, Feb 17 2025