A056516 - OEIS

%I #11 Oct 01 2019 19:47:20

%S 1,1,1,1,3,4,10,14,36,50,137,201,548,854,2417,3839,11060,18001,52599,

%T 86471,254982,421989,1252695,2079474,6196990,10306747,30795387,

%U 51263890,153409228,255514354,765389950,1275163904,3821990040,6368612099,19095299549,31821472593

%N Number of primitive (period n) periodic palindromic structures using a maximum of five different symbols.

%C For example, aaabbb is not a (finite) palindrome but it is a periodic palindrome. Permuting the symbols will not change the structure.

%D 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 Andrew Howroyd, <a href="/A056516/b056516.txt">Table of n, a(n) for n = 0..200</a>

%F a(n) = Sum_{d|n} mu(d)*A056506(n/d) for n > 0.

%F Moebius transform of A056506. - _T. D. Noe_, Oct 25 2006

%F a(n) = Sum_{k=1..5} A285037(n, k) for n > 0. - _Andrew Howroyd_, Oct 01 2019

%Y Cf. A056479, A056506, A285037.

%K nonn

%O 0,5

%A _Marks R. Nester_

%E Corrected by _T. D. Noe_, Oct 25 2006

%E a(0)=1 prepended and terms a(17) and beyond from _Andrew Howroyd_, Oct 01 2019