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A320548
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Number of partitions of n into parts of exactly six sorts which are introduced in ascending order such that sorts of adjacent parts are different.
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3
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1, 16, 157, 1223, 8331, 52078, 307123, 1738442, 9552826, 51357799, 271624228, 1418856967, 7341442171, 37708533544, 192586163135, 979219603193, 4961598120154, 25071026570558, 126410385741982, 636282269651863, 3198360710675384, 16059685006324807
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OFFSET
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6,2
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LINKS
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FORMULA
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MAPLE
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b:= proc(n, i, k) option remember; `if`(n=0 or i=1, k^(n-1),
b(n, i-1, k) +`if`(i>n, 0, k*b(n-i, i, k)))
end:
A:= (n, k)-> `if`(n=0, 1, `if`(k<2, k, k*b(n$2, k-1))):
a:= n-> (k-> add(A(n, k-i)*(-1)^i/(i!*(k-i)!), i=0..k))(6):
seq(a(n), n=6..40);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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