This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A386569 #12 Jul 30 2025 22:47:06
%S A386569 1,1,2,3,5,10,18,34,67,131,261,520,1037,2073,4143,8283,16562,33121,
%T A386569 66237,132471,264938,529870,1059740,2119473,4238941,8477878,16955748,
%U A386569 33911492,67822978,135645949,271291894,542583782,1085167557,2170335106,4340670206,8681340402
%N A386569 The number of binary self numbers not exceeding 2^n.
%F A386569 Limit_{n->oo} a(n)/2^n = A242403.
%e A386569 There are 3 binary self numbers that do no exceed 2^3 = 8: 1, 4 and 6. Hence a(3) = 3.
%t A386569 selfQ[n_] := AllTrue[Range[n, n - Floor@Log2[n], -1], # + DigitCount[#, 2, 1] != n &]; a[n_] := Count[Range[2^n], _?selfQ]; Array[a, 16, 0]
%Y A386569 Cf. A010061, A242403, A337078, A382452, A386568.
%K A386569 nonn,base
%O A386569 0,3
%A A386569 _Amiram Eldar_, Jul 26 2025