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 A132221 #11 Oct 22 2024 10:07:38 %S A132221 0,0,0,3,0,12,0,43,23,36,0,295,0,59,98,1932,0,979,0,1113,155,55,0, %T A132221 24995,183,89,2377,1840,0,5708,0,2801317,158,113,401,121257,0,72,304, %U A132221 315834,0,9487,0,2109,10914,54,0 %N A132221 Number of imprimitive transitive permutation groups of degree n. %C A132221 Smallest degree of an imprimitive group is 4. The groups of degree 4 are C_4, V_4, D_4. %C A132221 Imprimitive groups do not exist with prime degrees. %F A132221 a(n) = A002106(n) - A000019(n). %Y A132221 Cf. A000019, A002106. %K A132221 nonn,hard,more %O A132221 1,4 %A A132221 _Artur Jasinski_, Aug 14 2007 %E A132221 More terms from _Vaclav Kotesovec_, Jul 18 2022