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Numbers n such that 2^n has odd digit sum.
2

%I #5 Oct 11 2019 15:10:58

%S 0,4,5,7,8,10,12,16,18,19,20,22,23,24,25,27,28,29,30,31,34,35,38,39,

%T 40,48,49,52,53,56,59,62,63,66,68,69,72,75,81,87,88,89,92,93,94,96,97,

%U 99,100,101,104,105,108,109,110,111,114,118,119,121,125,127,131,132,133

%N Numbers n such that 2^n has odd digit sum.

%t Select[Range[0, 133], Mod[ Plus @@ IntegerDigits[2^# ], 2] == 1 &] (* _Ray Chandler_, Jun 10 2006 *)

%Y Cf. A118732, A118735, A076203.

%K base,nonn

%O 1,2

%A _Zak Seidov_, May 22 2006