login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Number of length n primitive (aperiodic) palindromes with integer entries that cover an initial interval of positive integers.
3

%I #8 Oct 03 2019 20:59:32

%S 1,1,0,2,2,12,10,74,72,538,528,4682,4668,47292,47218,545820,545760,

%T 7087260,7086710,102247562,102247020,1622632496,1622627890,

%U 28091567594,28091562840,526858348368,526858301088,10641342969902,10641342923148,230283190977852,230283190431480

%N Number of length n primitive (aperiodic) palindromes with integer entries that cover an initial interval of positive integers.

%H Andrew Howroyd, <a href="/A327874/b327874.txt">Table of n, a(n) for n = 0..200</a>

%F a(n) = Sum_{d|n} mu(n/d)*A000670(ceiling(d/2)) for n > 0.

%o (PARI) a(n) = {if(n<1, n==0, sumdiv(n, d, moebius(n/d)*sum(k=1, ceil(d/2), k!*stirling(ceil(d/2), k, 2))))}

%Y Row sums of A327873.

%Y Cf. A000670, A327879.

%K nonn

%O 0,4

%A _Andrew Howroyd_, Sep 28 2019