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A214617
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Primes written in the factorial base.
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2
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10, 11, 21, 101, 121, 201, 221, 301, 321, 1021, 1101, 1201, 1221, 1301, 1321, 2021, 2121, 2201, 2301, 2321, 3001, 3101, 3121, 3221, 4001, 4021, 4101, 4121, 4201, 4221, 10101, 10121, 10221, 10301, 11021, 11101, 11201, 11301, 11321, 12021, 12121, 12201, 12321
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OFFSET
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1,1
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COMMENTS
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The factorial base system uses 1!, 2!, 3!, ..., n! instead of powers of b, b^0, b^1, b^2, ... for some base b.
To be consistent with the normal base 10 system, the largest factorial used appears on the left.
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LINKS
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FORMULA
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EXAMPLE
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prime(6) = 13 = 2*3! + 1! so a(6) = 201.
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MAPLE
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b:= proc(n, i) local r; `if`(n<i, n,
10*b(iquo(n, i, 'r'), i+1)+ r)
end:
a:= n-> b(ithprime(n), 2):
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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