A327879 - OEIS

%I #8 Oct 03 2019 20:59:45

%S 1,1,1,2,6,12,40,74,300,538,2598,4682,25938,47292,296488,545820,

%T 3816240,7087260,54666830,102247562,862437450,1622632496,14857095400,

%U 28091567594,277474931700,526858348368,5584100612118,10641342969902,120462266677578

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

%H Andrew Howroyd, <a href="/A327879/b327879.txt">Table of n, a(n) for n = 0..200</a>

%F Moebius transform of A327868.

%e The a(4) = 6 primitive periodic palindromes are:

%e   1122, 1112, 1222,

%e   1213, 1232, 1323.

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

%Y Row sums of A327878.

%Y Cf. A327868, A327874.

%K nonn

%O 0,4

%A _Andrew Howroyd_, Sep 28 2019