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A229544
Numbers n such that n*product_of_digits(n) is a nonzero cube.
0
1, 8, 243, 784, 7776, 9826, 13122, 24389, 26244, 39366, 47628, 55566, 59895, 71442, 82944, 122825, 124416, 226981, 263424, 275625, 316368, 323433, 333396, 588245, 663255, 774144, 843648, 1339893, 1492992, 1613472, 2341344, 3816336, 3981312, 8719893, 8992364, 9393931, 9927988, 11212884, 11239424, 14823774
OFFSET
1,2
EXAMPLE
7776*(7*7*7*6) = 1600030008 = 252^3. Thus, 7776 is a member of this sequence.
PROG
(Python)
def DP(n):
..p = 1
..for i in str(n):
....p *= int(i)
..return p
def a(n):
..k = 0
..while k < n:
....if k**3 == n*DP(n):
......return n
....if k**3 > n*DP(n):
......return 0
....k += 1
n = 1
while n < 10**6:
..if a(n):
....print(n, end=', ')
..n += 1
# Simplified by Derek Orr, Mar 22 2015
(PARI) for(n=1, 10^7, d=digits(n); p=prod(i=1, #d, d[i]); if(p&&ispower(n*p, 3), print1(n, ", "))) \\ Derek Orr, Mar 22 2015
CROSSREFS
Sequence in context: A272236 A272239 A227319 * A115613 A209540 A085524
KEYWORD
nonn,base
AUTHOR
Derek Orr, Sep 25 2013
EXTENSIONS
Corrected and extended by Derek Orr, Mar 22 2015
STATUS
approved