|
%I #13 Nov 26 2016 03:04:17
%S 1,6,22,28,78,90,108,120,286,310,346,370,412,436,472,496,1086,1134,
%T 1206,1254,1338,1386,1458,1506,1596,1644,1716,1764,1848,1896,1968,
%U 2016,4222,4318,4462,4558,4726,4822,4966,5062,5242,5338,5482,5578,5746,5842,5986
%N Folding numbers with an odd number of bits (see A277238 for definition).
%C Terms greater than 1 are obtained by inserting a 1 in the middle of the binary expansions of the terms of A035928.
%H Lars Blomberg, <a href="/A276795/b276795.txt">Table of n, a(n) for n = 1..10000</a>
%e 78 is binary 1001110. There is a 1 in the center bit. The first 3 bits (100) and the last 3 reversed (011) sums to 111, so 78 is in the sequence.
%e 70 is binary 1000110. There is a 0 in the center bit, thus, despite the fact that the first and last 3 bits have the same relationship as above, 70 is not in the sequence.
%t {1}~Join~Select[Flatten@ Array[Range[#, 2 # - 1] &[2^#] &[2 (# - 1)] &, 7], If[OddQ@ Length@ # && Take[#, {Ceiling[Length[#]/2]}] == {0}, False, Union[Take[#, Floor[Length[#]/2]] + Reverse@ Take[#, -Floor[ Length[#]/2]]] == {1}] &@ IntegerDigits[#, 2] &] (* _Michael De Vlieger_, Nov 25 2016 *)
%Y Cf. A035928, A053738, A277238.
%K nonn,base
%O 1,2
%A _N. J. A. Sloane_, Nov 03 2016
%E More terms from _Lars Blomberg_, Nov 09 2016
|
