A136904 Numbers k such that k and k^2 use only the digits 0, 2, 4, 6 and 8.

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

Jonathan Wellons, Table of n, a(n) for n = 1..1038

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

Adjacent sequences: A136901 A136902 A136903 * A136905 A136906 A136907

Keyword

base,nonn

Author

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

Status

approved