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A261484 Number of set partitions of [n] into exactly eight parts such that no part contains two elements with a circular distance less than three. 2
1, 18, 210, 1980, 16467, 126126, 912338, 6332055, 42615547, 280182355, 1809148533, 11517941151, 72515126734, 452500330899, 2803547693199, 17270035728605, 105888136423278, 646765377652715, 3938163632325325, 23918395342393710, 144963673674486886 (list; graph; refs; listen; history; text; internal format)
OFFSET

8,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 8..1000

Index entries for linear recurrences with constant coefficients, signature (14,-70,231, -973,2800, -5291,17289, -28574,30709, -127043,26684, -91944,352921, 496104,584696, 276192,-496944, -518400,-518400).

FORMULA

G.f.: (720*x^11 +720*x^10 +580*x^9 +2204*x^8 +755*x^7 +1105*x^6 +392*x^5 +262*x^4 +69*x^3 +28*x^2 +4*x+1) *x^8 / ((x-1) *(6*x-1) *(5*x-1) *(3*x-1) *(2*x-1) *(4*x-1) *(x+1) *(x^2+x+1) *(5*x^2+x+1) *(3*x^2+x+1) *(4*x^2+x+1) *(2*x^2+x+1) *(6*x^2+x+1)).

EXAMPLE

a(8) = 1: 1|2|3|4|5|6|7|8.

a(9) = 18: 14|2|3|5|6|7|8|9, 15|2|3|4|6|7|8|9, 1|25|3|4|6|7|8|9, 16|2|3|4|5|7|8|9, 1|26|3|4|5|7|8|9, 1|2|36|4|5|7|8|9, 17|2|3|4|5|6|8|9, 1|27|3|4|5|6|8|9, 1|2|37|4|5|6|8|9, 1|2|3|47|5|6|8|9, 1|28|3|4|5|6|7|9, 1|2|38|4|5|6|7|9, 1|2|3|48|5|6|7|9, 1|2|3|4|58|6|7|9, 1|2|39|4|5|6|7|8, 1|2|3|49|5|6|7|8, 1|2|3|4|59|6|7|8, 1|2|3|4|5|69|7|8.

CROSSREFS

Column k=8 of A261477.

Sequence in context: A298988 A025959 A229270 * A004323 A025937 A021804

Adjacent sequences:  A261481 A261482 A261483 * A261485 A261486 A261487

KEYWORD

nonn,easy

AUTHOR

Alois P. Heinz, Aug 20 2015

STATUS

approved

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Last modified December 15 15:10 EST 2019. Contains 329999 sequences. (Running on oeis4.)