A235809 Numbers k such that k^3 has one or more occurrences of exactly seven different digits.
135, 145, 203, 221, 223, 225, 227, 233, 243, 244, 245, 247, 249, 254, 257, 265, 272, 273, 275, 276, 299, 313, 327, 329, 334, 338, 341, 345, 347, 352, 365, 366, 368, 382, 384, 388, 393, 395, 398, 403, 405, 409, 411, 412, 434, 439, 447, 452, 455, 473, 486, 493
Offset: 1
Examples
135 is in the sequence because 135^3 = 2460375, which contains exactly seven different digits.
Links
- Colin Barker, Table of n, a(n) for n = 1..1000
Programs
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Magma
[n: n in [0..1200] | #Set(Intseq(n^3)) eq 7]; // Vincenzo Librandi, Nov 07 2014
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Mathematica
Select[Range[500], Length[Union[IntegerDigits[#^3]]]==7&] (* Vincenzo Librandi, Nov 07 2014 *)
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PARI
s=[]; for(n=1, 600, if(#vecsort(eval(Vec(Str(n^3))),,8)==7, s=concat(s, n))); s
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PARI
for(n=0,10^3,if(#Set(digits(n^3))==7,print1(n,", "))); \\ Joerg Arndt, Nov 10 2014
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Python
from itertools import count, islice def A235809gen(): return filter(lambda n:len(set(str(n**3))) == 7,count(0)) A235809_list = list(islice(A235809gen(),26)) # Chai Wah Wu, Dec 23 2021