%I #25 Aug 06 2023 03:07:11
%S 3,4,9,14,18,21,24,31,39,41,46,50,53,56,63,79,83,84,89,94,102,104,111,
%T 115,116,121,126,158,166,168,175,179,180,185,190,206,210,213,216,223,
%U 231,233,238,242,245,248,255,319,335,339,340,345,350,358,360,367,371
%N a(1) = 3 , for n > 1 a(n) is the least number greater than a(n-1) such that the Hamming distance D(a(n-1),a(n)) = 3.
%C Odious and evil terms are alternating (cf. A000069, A001969).
%H Amiram Eldar, <a href="/A207016/b207016.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Alois P. Heinz)
%t a[1] = 3; a[n_] := a[n] = Module[{k = a[n - 1], m = a[n-1] + 1}, While[DigitCount[BitXor[k, m], 2, 1] != 3, m++]; m]; Array[a, 100] (* _Amiram Eldar_, Aug 06 2023 *)
%o (PARI) list(n)=my(v=vector(n));v[1]=3;for(i=2,n,v[i]=v[i-1]; while(hammingweight(bitxor(v[i-1],v[i]++))!=3,));v \\ _Charles R Greathouse IV_, Mar 26 2013
%Y Cf. A000069, A000225, A001969, A205509, A205510, A205511, A205302, A205649, A205533, A122565, A206852, A206853.
%K nonn,base
%O 1,1
%A _Vladimir Shevelev_, Feb 14 2012