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 A364837 #63 Jan 14 2024 20:33:33
%S A364837 2,4,1,2,6,4,1,3,1,1,1,3,1,1,1,1,2,4,1,2,6,4,2,4,1,3,1,1,1,2,4,1,3,9,
%T A364837 9,8,7,5,2,8,8,6,4,1,3,9,9,9,9,9,8,7,5,2,8,7,6,3,1,2,5,3,1,1,1,3,1,1,
%U A364837 3,9,8,7,5,3,1,1,1,3,1,2,4,2,5,2,6,4,1,2
%N A364837 Initial digit of 2^(2^n) = A001146(n).
%C A364837 The sequence corresponds to the initial digit of 2vvn (since 2^(2^n) = ((((2^2)^2)^...)^2) (n times)), where vv indicates weak tetration (see links).
%C A364837 Conjecture: this sequence obeys Benford's law.
%C A364837 For any n > 1, the final digit of 2^(2^n) is 6.
%H A364837 Pointless Large numbers stuff by Cookiefonster, <a href="https://sites.google.com/site/pointlesslargenumberstuff/home/2/weakoperators">2.03 The Weak Hyper-Operators</a>.
%F A364837 a(n) = floor(2^(2^n)/10^floor(log_10(2^(2^n)))), for n > 0.
%F A364837 a(n) = A000030(A001146(n)).
%e A364837 a(5) = 4, since 2^(2^5) = 2^32 = 4294967296.
%t A364837 Join[{2},Table[Floor[2^(2^n)/10^Floor[Log10[2^(2^n)]]],{n,27}]] (* _Stefano Spezia_, Aug 10 2023 *)
%o A364837 (Python)
%o A364837 def A364837(n): return int(str(1<<(1<<n))[0]) # _Chai Wah Wu_, Sep 14 2023
%Y A364837 Cf. A000030, A001146, A362004, A364789, A364855.
%K A364837 nonn,base
%O A364837 0,1
%A A364837 _Marco Ripà_, Aug 10 2023
%E A364837 More terms from _Jinyuan Wang_, Aug 10 2023