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A136884 Numbers k such that k and k^2 use only the digits 0, 2, 3, 4 and 7. 1
0, 2, 20, 200, 2000, 20000, 200000, 2000000, 4740332, 20000000, 27204302, 47403320, 200000000, 272043020, 474033200, 2000000000, 2702734302, 2720430200, 4477474032, 4740332000, 20000000000, 27027343020, 27204302000, 44774740320, 47227474032, 47403320000, 200000000000, 270273430200, 272043020000, 447747403200 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Generated with DrScheme.
Once any term appears that is not a multiple of 10, every multiple of that term by a power of 10 is also a term, i.e., new terms can be generated by appending any number of zeros to previous terms. - Harvey P. Dale, May 02 2021
LINKS
J. Wellons, Tables of Shared Digits [archived]
EXAMPLE
47333227304302^2 = 2240434407040720377707707204.
MATHEMATICA
With[{c={0, 2, 3, 4, 7}}, Select[FromDigits/@Tuples[c, 12], SubsetQ[ c, IntegerDigits[ #^2]]&]] (* Harvey P. Dale, May 02 2021 *)
CROSSREFS
Sequence in context: A085586 A322298 A136902 * A093136 A037519 A037722
KEYWORD
base,nonn
AUTHOR
Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
STATUS
approved

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Last modified June 15 06:51 EDT 2024. Contains 373402 sequences. (Running on oeis4.)