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A137074
Numbers k such that k and k^2 use only the digits 2, 3, 4, 7 and 8.
1
2, 22, 28, 88, 278, 472, 478, 482, 2872, 2878, 4832, 47732, 47778, 47838, 48722, 48872, 272732, 278832, 287878, 887878, 2728338, 2788778, 4844878, 8847838, 27243878, 27244878, 27283472, 27828732, 28782438, 47373872, 47778482, 48344878, 48772778, 88477332, 88728732, 88734372, 273474832, 278284878, 288484372, 477223472, 477372378
OFFSET
1,1
COMMENTS
Generated with DrScheme.
LINKS
J. Wellons, Tables of Shared Digits [archived]
EXAMPLE
473738734783472^2 = 224428388834244823422724374784.
MATHEMATICA
With[{c={2, 3, 4, 7, 8}}, Select[Range[5000000], SubsetQ[c, IntegerDigits[#]]&&SubsetQ[ c, IntegerDigits[#^2]]&]] (* Harvey P. Dale, Mar 22 2023 *)
CROSSREFS
Sequence in context: A152243 A074160 A368406 * A137106 A053962 A111771
KEYWORD
base,nonn
AUTHOR
Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
STATUS
approved