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 A202170 Numbers n such that n^2 has only digits 0, 4 and 8. 2
 0, 2, 20, 22, 200, 202, 220, 298, 2000, 2002, 2020, 2022, 2200, 2202, 2980, 20000, 20002, 20020, 20022, 20200, 20220, 22000, 22002, 22020, 28998, 29800, 200000, 200002, 200020, 200022, 200200, 200202, 200220, 202000, 202002, 202200, 220000, 220002, 220020, 220200, 289980, 298000, 632522, 2000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS n = 2*m where m^2 has only digits 0, 1 and 2. - Robert Israel, Jul 17 2018 LINKS Robert Israel, Table of n, a(n) for n = 1..204 MAPLE Res:= NULL: for x from 0 to 3^12 do   L:= convert(x, base, 3);   y:= add(L[i]*10^(i-1), i=1..nops(L));   if issqr(y) then     Res:= Res, 2*sqrt(y)   fi od: Res; # Robert Israel, Jul 17 2018 PROG (PARI) is_A202170(n)=!setminus(Set(Vec(Str(n^2))), Vec("048")) (MAGMA) [ n: n in [0..10^6 by 2] | Set(Intseq(n^2)) subset [0, 4, 8] ]; // Bruno Berselli, Dec 19 2011 CROSSREFS Cf. A030097, A058441. Includes 2*A136808. Sequence in context: A136885 A136909 A169965 * A136908 A196748 A144674 Adjacent sequences:  A202167 A202168 A202169 * A202171 A202172 A202173 KEYWORD nonn,base AUTHOR M. F. Hasler, Dec 13 2011 EXTENSIONS More terms from Robert Israel, Jul 17 2018 STATUS approved

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Last modified December 5 10:11 EST 2021. Contains 349543 sequences. (Running on oeis4.)