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 A077628 #11 Sep 19 2021 02:20:45
%S A077628 3,4,0,8,14,16,42,32,82,64,270,128,518,256,642,512,2126,1024,7098,
%T A077628 2048,7502,4096,14550,8192,19810,16384,108802,32768,101154,65536,
%U A077628 299166,131072,360298,262144,891666,524288,2128896,1048576,8352642,2097152,4466878
%N A077628 Sum of terms in periodic part of continued fraction expansion of square root of 1+2^n.
%H A077628 Chai Wah Wu, <a href="/A077628/b077628.txt">Table of n, a(n) for n = 1..78</a>
%t A077628 Table[Apply[Plus, Last[ContinuedFraction[Sqrt[1+2^u]]]], {u, 1, 25}]
%t A077628 Join[{3,4,3},Table[Total[ContinuedFraction[Sqrt[1+2^n]][[2]]],{n,4,50}]] (* _Harvey P. Dale_, Oct 03 2016 *)
%Y A077628 Cf. A077624-A077635.
%K A077628 nonn
%O A077628 1,1
%A A077628 _Labos Elemer_, Nov 13 2002
%E A077628 More terms from _Harvey P. Dale_, Oct 03 2016
%E A077628 a(3) corrected by _Chai Wah Wu_, Sep 18 2021