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A327879 Number of primitive (period n) periodic palindromes with integer entries that cover an initial interval of positive integers. 3
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

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

FORMULA

Moebius transform of A327868.

EXAMPLE

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

  1122, 1112, 1222,

  1213, 1232, 1323.

PROG

(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)}

CROSSREFS

Row sums of A327878.

Cf. A327868, A327874.

Sequence in context: A225957 A123045 A280171 * A094261 A080497 A127724

Adjacent sequences:  A327876 A327877 A327878 * A327880 A327881 A327882

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Sep 28 2019

STATUS

approved

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Last modified February 17 02:22 EST 2020. Contains 331976 sequences. (Running on oeis4.)