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A331543
Squares using only decimal digits 0,1,2,3.
1
0, 1, 100, 121, 10000, 10201, 12100, 12321, 22201, 123201, 130321, 1000000, 1002001, 1020100, 1022121, 1210000, 1212201, 1232100, 1320201, 2220100, 3101121, 12320100, 13032100, 100000000, 100020001, 100200100, 100220121, 102010000, 102030201, 102212100, 102232321, 103002201, 121000000, 121022001, 121220100
OFFSET
1,3
COMMENTS
If n is a member then so is 100*n.
All terms == 0, 1, 100, 121, 201 or 321 (mod 1000).
LINKS
EXAMPLE
a(3) = 100 is a member because 100 = 10^2 and 100 has no digits > 3.
MAPLE
Res:= NULL: count:= 0:
for k from 0 while count < 50 do
for j in [0, 1, 100, 121, 201, 321] do
L:= convert(k, base, 4);
x:= add(L[i]*10^(i-1), i=1..nops(L))*1000+j;
if issqr(x) then count:= count+1; Res:= Res, x fi
od od:
Res;
CROSSREFS
Cf. A030174.
Sequence in context: A365820 A095633 A228103 * A063009 A066139 A109881
KEYWORD
nonn,base
AUTHOR
Robert Israel, Jan 19 2020
STATUS
approved