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A208186 Number of distinct n-colored necklaces with 5 beads per color. 2
1, 1, 26, 50452, 586637256, 24934429725024, 2961088201992945120, 823940558733748910598720, 474389544274867071519255599040, 515190840198859838606483730223480320, 982409170121762644481286121423409538362880, 3106878824601775580798512171862746898249905228800 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
a(n) = Sum_{d|5} phi(5/d)*(n*d)!/(d!^n*n*5) if n>0 and a(0) = 1.
EXAMPLE
a(0) = 1: the empty necklace.
a(1) = 1: {00000}.
a(2) = 26: {0000011111, ..., 0101010101}.
MAPLE
with(numtheory);
a:= n-> `if`(n=0, 1, add(phi(5/d) *(n*d)!/(d!^n *5*n), d={1, 5})):
seq(a(n), n=0..12);
CROSSREFS
Row n=5 of A208183.
Sequence in context: A359052 A209961 A302396 * A316677 A092212 A365983
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 24 2012
STATUS
approved

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Last modified June 13 17:32 EDT 2024. Contains 373391 sequences. (Running on oeis4.)