|
%I #13 Dec 15 2023 16:31:07
%S 1,2,3,4,5,6,7,8,9,10,12,14,15,16,17,18,20,24,28,30,31,32,33,34,36,40,
%T 48,56,60,62,63,64,65,66,68,72,80,96,112,120,124,126,127,128,129,130,
%U 132,136,144,160,192,224,240,248,252,254,255,256,257,258,260,264,272
%N Numbers of the form 2^j +- 2^i for 0 <= i < j, in ascending order.
%C Positive sums and differences of pairs of distinct powers of two, sorted, with duplicates removed.
%H Ivan Neretin, <a href="/A129523/b129523.txt">Table of n, a(n) for n = 1..1602</a>
%F x(n) = { 2^x - 2^y if x < y }, { 2^x if x = y }, { 2^x + 2^y if x > y} where x = ceiling(sqrt(n)) and y = n - (x-1)^2 - 1.
%F Union of A018900 and A023758. - _M. F. Hasler_, Jul 31 2015
%e 1 = 2^1 - 2^0; 2 = 2^2 - 2^1; 3 = 2^1 + 2^0 or 2^2 - 2^0; 4 = 2^3 - 2^2; 5 = 2^2 + 2^0.
%t Union[Flatten[Table[{2^n, 2^n - 2^k, 2^n + 2^k}, {n, 8}, {k, 0, n - 1}]]] (* _Ivan Neretin_, Jul 29 2015 *)
%o (Octave) x=[]; m=12; for i = 0:m; x=[x,2^i-2.^([(i-2):-1:0]),2^i,2^i+2.^([0 :(i-2)])]; end; x
%K nonn
%O 1,2
%A Phil Rutschman (phil(AT)rsnsoft.com), Apr 19 2007
|
