OFFSET
1,2
EXAMPLE
For k = 11, k^2 = 121;
for k = 26, k^2 = 676.
MATHEMATICA
Select[Range[638], (d = IntegerDigits[#^2]; d[[1]] == d[[-1]]) &] (* Giovanni Resta, Jun 25 2018 *)
PROG
(PARI) for(n=1, 10^3, my(d=digits(n^2)); if( d[1]==d[#d], print1(n, ", "))); \\ Joerg Arndt, Jun 10 2018
(Python)
def ok(n): s = str(n*n); return s[0] == s[-1]
print(list(filter(ok, range(1, 639)))) # Michael S. Branicky, Jul 16 2021
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Neville Holmes, Jun 08 2018
STATUS
approved