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%I #13 Jul 13 2022 05:59:20
%S 5,17,20,65,68,80,257,260,272,320,1025,1028,1040,1088,1280,4097,4100,
%T 4112,4160,4352,5120,16385,16388,16400,16448,16640,17408,20480,65537,
%U 65540,65552,65600,65792,66560,69632,81920,262145,262148,262160,262208,262400,263168
%N Sums of 2 distinct powers of 4.
%H Amiram Eldar, <a href="/A038470/b038470.txt">Table of n, a(n) for n = 1..10000</a>
%t Sort[Plus @@@ Subsets[4^Range[0, 9], {2}]] (* _Amiram Eldar_, Jul 13 2022 *)
%o (Python)
%o def aupto(limit):
%o p = [4**i for i in range(limit//4+1) if 4**i < limit]
%o p2 = set(a+b for i, a in enumerate(p) for b in p[i+1:] if a+b <= limit)
%o return sorted(p2)
%o print(aupto(265000)) # _Michael S. Branicky_, May 17 2021
%Y Base-4 interpretation of A038444.
%Y Cf. A000302, A038471, A038472, A038473.
%K nonn,easy
%O 1,1
%A _Olivier Gérard_
%E Offset corrected by _Amiram Eldar_, Jul 13 2022