A376897 Positive numbers k such that all the digits in the octal expansion of k^2 are distinct.

1, 2, 4, 5, 7, 13, 14, 15, 18, 20, 21, 28, 30, 37, 39, 43, 44, 45, 53, 55, 63, 78, 84, 103, 110, 113, 117, 127, 149, 155, 156, 161, 162, 172, 173, 174, 175, 179, 220, 236, 242, 270, 286, 293, 299, 301, 340, 343, 350, 356, 361, 395, 407, 412, 425, 439, 461, 475, 499, 674, 819, 1001, 1211, 1230, 1244, 1323, 1764, 2450, 2751, 3213

Offset: 1

Author

Kalle Siukola, Oct 08 2024

Keywords

• base
• fini
• full
• nonn

Comments

There are no terms >= 2^12 because 2^24-1 is the largest eight-digit octal number.

Examples

			110 is in the sequence because 110^2 = 12100 = 27504_8 and no octal digit occurs more than once.
		

Crossrefs

Cf. A007094, A119509, A376898.

Programs

Mathematica

Select[Range[2^12], DuplicateFreeQ[IntegerDigits[#^2, 8]] &] (* Michael De Vlieger, Oct 12 2024 *)

Python

for k in range(1, 2**12):
    octal = format(k**2, "o")
    if len(octal) == len(set(octal)): print(k, end=",")