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A304391 Numbers that are the number of permutations of a set of balls of at least three distinct colors. 0
6, 12, 20, 24, 30, 42, 56, 60, 72, 90, 105, 110, 120, 132, 140, 156, 168, 180, 182, 210, 240, 252, 272, 280, 306, 336, 342, 360, 380, 420, 462, 495, 504, 506, 552, 560, 600, 630, 650, 660, 702, 720, 756, 812, 840, 858, 870, 930, 990, 992, 1056, 1092, 1120, 1122, 1190 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

FORMULA

A027480(k) = k * (k + 1) * (k + 2) / 2 is in the sequence for k >= 2.

EXAMPLE

There are 30 permutations of 5 balls where 2 are red, 2 are yellow and 1 is blue.

CROSSREFS

A002378 is a subsequence.

Cf. A027480, A304938.

Sequence in context: A105455 A246198 A083207 * A145278 A094371 A286927

Adjacent sequences:  A304388 A304389 A304390 * A304392 A304393 A304394

KEYWORD

nonn,easy

AUTHOR

David A. Corneth, May 24 2018

STATUS

approved

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Last modified May 26 01:01 EDT 2020. Contains 334613 sequences. (Running on oeis4.)