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%I #19 Oct 12 2024 22:32:50
%S 1,2,4,5,7,13,14,15,18,20,21,28,30,37,39,43,44,45,53,55,63,78,84,103,
%T 110,113,117,127,149,155,156,161,162,172,173,174,175,179,220,236,242,
%U 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
%N Positive numbers k such that all the digits in the octal expansion of k^2 are distinct.
%C There are no terms >= 2^12 because 2^24-1 is the largest eight-digit octal number.
%e 110 is in the sequence because 110^2 = 12100 = 27504_8 and no octal digit occurs more than once.
%t Select[Range[2^12], DuplicateFreeQ[IntegerDigits[#^2, 8]] &] (* _Michael De Vlieger_, Oct 12 2024 *)
%o (Python)
%o for k in range(1, 2**12):
%o octal = format(k**2, "o")
%o if len(octal) == len(set(octal)): print(k, end=",")
%Y Cf. A007094, A119509, A376898.
%K base,fini,full,nonn
%O 1,2
%A _Kalle Siukola_, Oct 08 2024