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A137066 Numbers k such that k and k^2 use only the digits 2, 3, 4 and 5. 1
2, 5, 235, 2335, 23335, 233335, 2333335, 2354235, 23333335, 233333335, 2333333335, 2333524235, 23333333335, 23333524235, 233333333335, 2333333333335, 23333333333335, 233333333333335, 2333333333333335, 23333333333333335, 233333333333333335 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Generated with DrScheme.
Contains 2*10^m + (10^m-1)/3 + 2 for m >= 2. Are these all the terms > 23333524235? There are no others with up to 25 digits. - Robert Israel, Jul 02 2018
There are no others than those of that form with up to 35 digits. - Michael S. Branicky, May 25 2021
LINKS
Jonathan Wellons, Tables of Shared Digits
EXAMPLE
23333524235^2 = 544453353225332335225.
PROG
(PARI) isokd(x) = (x < 2) || (x > 5);
isok(n) = !#select(x->isokd(x), digits(n)) && !#select(x->isokd(x), digits(n^2)); \\ Michel Marcus, Jul 02 2018
(Python) # uses auptod in A137110
print(auptod(16, only="2345")) # Michael S. Branicky, May 25 2021
CROSSREFS
Cf. A137110.
Sequence in context: A249180 A135724 A137068 * A175977 A121270 A085603
KEYWORD
base,nonn
AUTHOR
Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
STATUS
approved

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Last modified September 30 03:10 EDT 2023. Contains 365781 sequences. (Running on oeis4.)