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%I #7 May 02 2015 11:05:22
%S 1,9,33,129,513,1175,2049,4617,8193,18441,18807,32769,73737,131073,
%T 264321,270369,294921,524289,545431,1081377,1179657,2097153,4203009,
%U 4325409,4718601,8388609,16810497,16908417,17301537,18874377,33554433,38729961,67143681,67633281,69206049
%N Numbers n not divisible by 2 such that n^2 written in base 4 has no digit > 1.
%C The first condition is added to exclude terms of the form a(k)*2^m (m>0), whose square would just have 0's appended w.r.t. a(k)^2 when written in base 4, and therefore trivially have no digit > 1 in base 4.
%C See A230030 for the base 5 analog, which is much more challenging.
%o (PARI) b=4;forstep(n=1,10^8,2,vecmax(digits(n^2,b))>1||print1(n","))
%Y Cf. A257283 (base 3 analog), A230030 (base 5 analog).
%K nonn,base
%O 1,2
%A _M. F. Hasler_, May 02 2015
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