A137074 Numbers k such that k and k^2 use only the digits 2, 3, 4, 7 and 8.

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

Jonathan Wellons, Table of n, a(n) for n = 1..169

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

Adjacent sequences: A137071 A137072 A137073 * A137075 A137076 A137077

Keyword

base,nonn,changed

Author

Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008

Status

approved