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 A056668 #8 May 19 2024 12:46:31 %S A056668 256,2148007936,56713727820157015040139002378207625216, %T A056668 558658663747608212482251041591910255311640242524683057405682390247387063055565341158714756695500587176090293978181121308657577535237991794589785900711936 %N A056668 Number of equivalence classes of 4-valued Post functions of n variables under action of symmetric group S_n. %H A056668 M. A. Harrison and R. G. High, <a href="https://doi.org/10.1016/S0021-9800(68)80008-0">On the cycle index of a product of permutation groups</a>, J. Combin. Theory, 4 (1968), 277-299. See p. 295. %Y A056668 Cf. A000616, A001321, A001322, A001323, A001324. %K A056668 nonn %O A056668 1,1 %A A056668 _Vladeta Jovovic_, Aug 09 2000