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 A056516 #11 Oct 01 2019 19:47:20
%S A056516 1,1,1,1,3,4,10,14,36,50,137,201,548,854,2417,3839,11060,18001,52599,
%T A056516 86471,254982,421989,1252695,2079474,6196990,10306747,30795387,
%U A056516 51263890,153409228,255514354,765389950,1275163904,3821990040,6368612099,19095299549,31821472593
%N A056516 Number of primitive (period n) periodic palindromic structures using a maximum of five different symbols.
%C A056516 For example, aaabbb is not a (finite) palindrome but it is a periodic palindrome. Permuting the symbols will not change the structure.
%D A056516 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 A056516 Andrew Howroyd, <a href="/A056516/b056516.txt">Table of n, a(n) for n = 0..200</a>
%F A056516 a(n) = Sum_{d|n} mu(d)*A056506(n/d) for n > 0.
%F A056516 Moebius transform of A056506. - _T. D. Noe_, Oct 25 2006
%F A056516 a(n) = Sum_{k=1..5} A285037(n, k) for n > 0. - _Andrew Howroyd_, Oct 01 2019
%Y A056516 Cf. A056479, A056506, A285037.
%K A056516 nonn
%O A056516 0,5
%A A056516 _Marks R. Nester_
%E A056516 Corrected by _T. D. Noe_, Oct 25 2006
%E A056516 a(0)=1 prepended and terms a(17) and beyond from _Andrew Howroyd_, Oct 01 2019