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 A056354 #8 Oct 25 2019 16:39:27 %S A056354 1,1,2,3,7,11,33,73,237,703,2433,8309,30108,108991,403262,1497070, %T A056354 5607437,21076571,79595990,301492045,1145560579,4363503684, %U A056354 16660204452,63741248201,244339646708,938255682551,3608668388957,13900021844558,53614340398327,207062143625711 %N A056354 Number of bracelet structures using a maximum of four different colored beads. %C A056354 Turning over will not create a new bracelet. Permuting the colors of the beads will not change the structure. %D A056354 M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2] %H A056354 Andrew Howroyd, <a href="/A056354/b056354.txt">Table of n, a(n) for n = 0..200</a> %F A056354 Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference. %F A056354 a(n) = Sum_{k=1..4} A152176(n, k) for n > 0. - _Andrew Howroyd_, Oct 25 2019 %Y A056354 Cf. A056292, A152176. %K A056354 nonn %O A056354 0,3 %A A056354 _Marks R. Nester_ %E A056354 a(0)=1 prepended and terms a(26) and beyond from _Andrew Howroyd_, Oct 25 2019