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 A364271 #20 Dec 19 2024 11:45:36
%S A364271 0,1,2,3,1,7,1,7,2,8,1,1,1,2,7,1,9,1,2,2,4,5,1,7,3,2,4,1,2,6,2,1,2,2,
%T A364271 1,8,1,6,1,5,2,8,8,3,9,3,4,2,4,3,1,6,2,1,6,6,9,1,9,2,5,2,9,9,6,8,4,2,
%U A364271 7,7,6,1,2,2,3,1,2,6,1,1,6,1,1,2,3,5,1
%N A364271 Initial digit of n^((n + 1)^(n + 2)).
%H A364271 Kevin Ryde, <a href="/A364271/a364271.c.txt">C code using MPFR</a>
%F A364271 a(n) = floor(t / 10^floor(log_10(t))) where t = n^((n + 1)^(n + 2)).
%F A364271 a(n) = A000030(A030198(n)).
%e A364271 a(2) = 2, since 2^((2 + 1)^(2 + 2)) = 2417851639229258349412352.
%t A364271 Join[{0}, Table[Floor[n^((n+1)^(n+2))/10^Floor[Log10[n^((n+1)^(n+2))]]], {n, 86}]]
%o A364271 (C) /* See links */
%Y A364271 Cf. A000030, A030198, A365689 (final digit).
%K A364271 nonn,base
%O A364271 0,3
%A A364271 _Marco Ripà_, Oct 20 2023
%E A364271 More terms from _Kevin Ryde_, Oct 27 2023