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A018142
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Powers of fifth root of 10 rounded to nearest integer.
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3
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1, 2, 3, 4, 6, 10, 16, 25, 40, 63, 100, 158, 251, 398, 631, 1000, 1585, 2512, 3981, 6310, 10000, 15849, 25119, 39811, 63096, 100000, 158489, 251189, 398107, 630957, 1000000, 1584893, 2511886, 3981072, 6309573
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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LINKS
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Chai Wah Wu, Table of n, a(n) for n = 0..1000
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FORMULA
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a(n) = round(10^(n/5)). - Wesley Ivan Hurt, Jun 23 2015
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MAPLE
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A018142:=n->round(10^(n/5)): seq(A018142(n), n=0..50); # Wesley Ivan Hurt, Jun 23 2015
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PROG
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(Python)
from gmpy2 import iroot_rem
def A018142(n):
i, j = iroot_rem(10**n, 5)
return int(i) + int(32*j >= 10*i*(4*i*(2*i*(i + 1) + 1) + 1) + 1) # Chai Wah Wu, Aug 18 2016
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CROSSREFS
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Sequence in context: A072944 A024722 A024965 * A173697 A017986 A343304
Adjacent sequences: A018139 A018140 A018141 * A018143 A018144 A018145
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KEYWORD
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nonn,easy
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AUTHOR
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N. J. A. Sloane
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STATUS
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approved
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