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A326895 Number of chiral pairs of color loops of length n with integer entries that cover an initial interval of positive integers. 4
0, 0, 1, 6, 48, 370, 3341, 33966, 393468, 5111100, 73753685, 1170469192, 20263758984, 380047816638, 7676106093049, 166114206920706, 3834434320842720, 94042629507775794, 2442147034668044933, 66942194905680941268, 1931543452344523778392, 58519191359156026158522 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..200

FORMULA

Inverse Moebius transform of A326888.

PROG

(PARI) a(n)={sum(k=1, n, -k!*(stirling((n+1)\2, k, 2) + stirling(n\2+1, k, 2))/4 + k!*sumdiv(n, d, eulerphi(d)*stirling(n/d, k, 2))/(2*n))} \\ Andrew Howroyd, Sep 13 2019

CROSSREFS

Row sums of A305541.

Cf. A326888.

Sequence in context: A324074 A052625 A326888 * A291033 A155130 A250164

Adjacent sequences:  A326892 A326893 A326894 * A326896 A326897 A326898

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Sep 13 2019

STATUS

approved

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Last modified September 19 17:19 EDT 2021. Contains 347564 sequences. (Running on oeis4.)