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A018142
Powers of fifth root of 10 rounded to nearest integer.
5
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
OFFSET
0,2
FORMULA
a(n) = round(10^(n/5)). - Wesley Ivan Hurt, Jun 23 2015
MAPLE
A018142:=n->round(10^(n/5)): seq(A018142(n), n=0..50); # Wesley Ivan Hurt, Jun 23 2015
MATHEMATICA
Round[(10^(Range[0, 50]/5))] (* Paolo Xausa, Jul 02 2024 *)
PROG
(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
CROSSREFS
Cf. A011095.
Sequence in context: A072944 A024722 A024965 * A173697 A017986 A343304
KEYWORD
nonn,easy
STATUS
approved