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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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Generated with DrScheme. Subsequence of A014263. - Michel Marcus, Oct 04 2013 LINKS Jonathan Wellons, Table of n, a(n) for n = 1..1038 J. Wellons, Tables of Shared Digits 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 Adjacent sequences: A136901 A136902 A136903 * A136905 A136906 A136907 KEYWORD base,nonn AUTHOR Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008 STATUS approved

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Last modified December 8 17:58 EST 2023. Contains 367680 sequences. (Running on oeis4.)