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A056582
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Highest common factor (or GCD) of n^n and hyperfactorial(n-1), i.e., gcd(n^n, product(k^k) for k < n).
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3
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1, 1, 4, 1, 1728, 1, 65536, 19683, 3200000, 1, 8916100448256, 1, 13492928512, 437893890380859375, 18446744073709551616, 1, 39346408075296537575424, 1, 104857600000000000000000000
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OFFSET
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2,3
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COMMENTS
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Sequence could be defined as: a(2) = 1, a(4) = 4, a(8) = 65536, a(9) = 19683; if p an odd prime: a(p) = 1 and a(2p) = (4p)^p; otherwise if n > 1: a(n) = n^n.
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LINKS
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FORMULA
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EXAMPLE
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a(6) = gcd(46656, 86400000) = 1728.
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PROG
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(Python)
from gmpy2 import gcd
for i in range(2, 201):
m = i**i
A056582_list.append(int(gcd(n, m)))
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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