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A030697 Smallest nontrivial extension of n-th cube which is a cube not ending 000. 2
125, 85184, 2744, 6434856, 1259712, 2161700757, 34328125, 5124031424, 7290099019, 10007873875, 13312053, 172808693, 21975528401, 274498269499, 337589698347, 409675763483, 491355848971, 58320792152, 68593724400375 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

PROG

(Python)

from gmpy2 import iroot

def A030697(n):

    d, nd = 10, 10*n**3

    while True:

        x = iroot(nd-1, 3)[0]+1

        if not x % 10:

            x += 1

        x = x**3

        if x < nd+d:

            return int(x)

        d *= 10

        nd *= 10 # Chai Wah Wu, May 24 2016

CROSSREFS

Cf. A030698.

Sequence in context: A194654 A222277 A013783 * A265623 A050640 A161354

Adjacent sequences:  A030694 A030695 A030696 * A030698 A030699 A030700

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

STATUS

approved

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Last modified July 23 15:58 EDT 2019. Contains 325258 sequences. (Running on oeis4.)