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A136904
Numbers k such that k and k^2 use only the digits 0, 2, 4, 6 and 8.
4
0, 2, 8, 20, 22, 68, 80, 200, 202, 220, 262, 668, 680, 800, 2000, 2002, 2020, 2022, 2200, 2202, 2620, 6668, 6680, 6800, 8000, 8262, 20000, 20002, 20020, 20022, 20200, 20220, 20602, 22000, 22002, 22020, 24622, 26200, 66668, 66680, 66800, 68000, 80000, 82620, 200000, 200002, 200020, 200022, 200200, 200202, 200220, 202000, 202002, 202200, 206020
OFFSET
1,2
COMMENTS
Generated with DrScheme.
Subsequence of A014263. - Michel Marcus, Oct 04 2013
LINKS
J. Wellons, Tables of Shared Digits [archived]
EXAMPLE
828268460602^2 = 686028642828006826202404.
PROG
(PARI) evdigs(n) = {if (n==0, return (1)); digs = digits(n); for (i = 1, #digs, if (digs[i] % 2, return (0)); ); return (1); }
isok(n) = evdigs(n) && evdigs(n^2); \\ Michel Marcus, Oct 04 2013
CROSSREFS
Sequence in context: A227399 A327098 A030097 * A043002 A108180 A233571
KEYWORD
base,nonn
AUTHOR
Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
STATUS
approved