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A285042 Number of primitive (period n) periodic palindromic structures of length n using an infinite alphabet. 4

%I

%S 1,1,1,1,3,4,10,14,36,50,138,202,562,876,2589,4134,12828,21146,69115,

%T 115974,398619,678554,2450202,4213596,15939338,27644432,109304036,

%U 190899270,787013630,1382958544,5931819804,10480142146,46673246440,82864869600,382473261356

%N Number of primitive (period n) periodic palindromic structures of length n using an infinite alphabet.

%C See A285037 for additional information. Permuting the symbols will not change the structure.

%H Andrew Howroyd, <a href="/A285042/b285042.txt">Table of n, a(n) for n = 0..500</a>

%F a(n) = Sum_{d | n} mu(n/d) * A285013(d) for n > 0.

%o (PARI) \\ Requires T from A285037.

%o seq(n)={my(A=T(n)); concat([1], vector(n, i, vecsum(A[i, ])))} \\ _Andrew Howroyd_, Oct 02 2019

%Y Row sums of A285037.

%Y Cf. A285013.

%K nonn

%O 0,5

%A _Andrew Howroyd_, Apr 08 2017

%E a(0)=1 prepended and terms a(28) and beyond from _Andrew Howroyd_, Oct 02 2019

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Last modified September 30 11:00 EDT 2022. Contains 357105 sequences. (Running on oeis4.)