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A237525 Numbers k such that the sum of digits of k^3 is a cube. 1
0, 1, 2, 5, 8, 10, 11, 20, 27, 33, 36, 39, 42, 50, 54, 57, 69, 72, 75, 78, 80, 84, 87, 93, 100, 101, 105, 108, 110, 111, 114, 135, 138, 147, 162, 165, 168, 174, 177, 200, 219, 222, 225, 228, 231, 234, 258, 267, 270, 273, 276, 285, 291, 294, 312 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

If k is in the sequence then so is 10*k. - David A. Corneth, May 26 2021

LINKS

David A. Corneth, Table of n, a(n) for n = 1..10866

FORMULA

a(n) = A053058(n)^(1/3).

EXAMPLE

36^3 = 46656. DigitSum(46656) = 27 (also a cube). So, 36 is a member of this sequence.

PROG

(Python)

def DigitSum(x):

..total = 0

..for i in str(x):

....total += int(i)

..return total

def DigSumCube(x):

..for n in range(10**10):

....if DigitSum(x**3) == n**3:

......return True

....if DigitSum(x**3) < n**3:

......return False

..return False

x = 1

while x < 1000:

..if DigSumCube(x):

....print(x)

..x += 1

(PARI) isok(n) = ispower(sumdigits(n^3), 3); \\ Michel Marcus, Feb 09 2014

CROSSREFS

Cf. A061910, A007953, A004164, A053058.

Sequence in context: A080228 A153052 A338388 * A290578 A294127 A166955

Adjacent sequences:  A237522 A237523 A237524 * A237526 A237527 A237528

KEYWORD

nonn,base

AUTHOR

Derek Orr, Feb 09 2014

STATUS

approved

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Last modified June 12 16:05 EDT 2021. Contains 344959 sequences. (Running on oeis4.)