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 A163860 #13 Aug 12 2023 23:00:45 %S A163860 1,1,3,12,73,580,5721,69244,1000210,16319601,297453340 %N A163860 Number of different 4th-power (quartic) mappings of a finite set of n elements into itself. %C A163860 The same as A102687 for square composition, as A163859 for cubic compositions, here a(n) is the number of different mappings g that admit at least one mapping f as the 4th-order root (g=fofofof) in terms of the composition. %Y A163860 Cf. A102687, A163859. %Y A163860 Column k=4 of A247026. %K A163860 more,nonn %O A163860 0,3 %A A163860 _Carlos Alves_, Aug 05 2009 %E A163860 a(0) from _Alois P. Heinz_, Sep 09 2014 %E A163860 a(8)-a(10) from _Bert Dobbelaere_, Jan 24 2019