OFFSET
1,1
COMMENTS
The sequence is infinite.
EXAMPLE
a(6) = 71132356 = 8464^2 contains 2, 3, 5, 7, 11 and 13 as substrings and no smaller square has that property.
MATHEMATICA
Do[k = 1; While[! AllTrue[Prime@ Range@ n, StringContainsQ[ToString[k^2], ToString@ #] &], k++]; Print[k^2], {n, 9}] (* Michael De Vlieger, Oct 19 2015, Version 10 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Emmanuel Vantieghem, Oct 17 2015
EXTENSIONS
a(15)-a(16) from Bert Dobbelaere, Oct 28 2018
a(17)-a(18) from Giovanni Resta, Aug 27 2019
STATUS
approved