A327879 Number of primitive (period n) periodic palindromes with integer entries that cover an initial interval of positive integers.

1, 1, 1, 2, 6, 12, 40, 74, 300, 538, 2598, 4682, 25938, 47292, 296488, 545820, 3816240, 7087260, 54666830, 102247562, 862437450, 1622632496, 14857095400, 28091567594, 277474931700, 526858348368, 5584100612118, 10641342969902, 120462266677578

Offset: 0

Author

Andrew Howroyd, Sep 28 2019

Keywords

• nonn

Examples

			The a(4) = 6 primitive periodic palindromes are:
  1122, 1112, 1222,
  1213, 1232, 1323.
		

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..200

Crossrefs

Row sums of A327878.

Cf. A327868, A327874.

Programs

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)}

Formula

Moebius transform of A327868.