login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A136818
Numbers k such that k and k^2 use only the digits 0, 1, 2, 4 and 6.
1
0, 1, 2, 4, 10, 11, 12, 20, 21, 40, 46, 100, 101, 102, 110, 120, 121, 142, 162, 200, 201, 204, 210, 400, 402, 460, 642, 1000, 1001, 1002, 1010, 1011, 1012, 1020, 1021, 1100, 1101, 1102, 1200, 1201, 1210, 1420, 1620, 2000, 2001, 2004, 2010, 2011, 2040, 2100, 2101, 2462, 4000, 4002, 4020, 4600, 6404, 6420, 6642, 10000, 10001, 10002, 10010, 10011, 10012, 10020
OFFSET
1,3
COMMENTS
Generated with DrScheme.
LINKS
J. Wellons, Tables of Shared Digits [archived]
EXAMPLE
641416101^2 = 411414614622042201.
MATHEMATICA
Module[{c={0, 1, 2, 4, 6}}, Select[FromDigits/@Tuples[c, 5], SubsetQ[c, IntegerDigits[ #^2]]&]] (* Harvey P. Dale, Aug 27 2022 *)
CROSSREFS
Sequence in context: A184876 A243622 A178713 * A293556 A029984 A101519
KEYWORD
base,nonn
AUTHOR
Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
STATUS
approved