OFFSET
1,3
LINKS
G. J. Simmons, On palindromic squares of non-palindromic numbers, J. Rec. Math., 5 (No. 1, 1972), 11-19. [Annotated scanned copy]
EXAMPLE
From Mattew Bondar, Mar 12 2021: (Start)
111_4 = 21_10, 21^2 = 441, 441_10 = 12321_4 (palindrome).
1013_4 = 71_10, 71^2 = 5041, 5041_10 = 1032301_4 (palindrome). (End)
MATHEMATICA
FromDigits /@ IntegerDigits[Select[Range[0, 2^17], PalindromeQ@ IntegerDigits[#^2, 4] &], 4] (* Michael De Vlieger, Mar 13 2021 *)
PROG
(Python)
def decimal_to_quaternary(n):
if n == 0:
return '0'
b = ''
while n > 0:
b = str(n % 4) + b
n = n // 4
return b
x = 0
counter = 0
while True:
y = decimal_to_quaternary(x ** 2)
if y == y[::-1]:
print(int(decimal_to_quaternary(x)))
counter += 1
x += 1 # Mattew Bondar, Mar 10 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Oct 22 2015
STATUS
approved