A331543 Squares using only decimal digits 0,1,2,3.

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

Robert Israel, Table of n, a(n) for n = 1..400

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

Adjacent sequences: A331540 A331541 A331542 * A331544 A331545 A331546

Keyword

nonn,base

Author

Robert Israel, Jan 19 2020

Status

approved