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 A138029 #6 Jan 15 2019 18:46:29
%S A138029 1,2,9,6,6,7,1,2,4,1,2,7,2,7,2,1,4,2,1,5,2,1,9,5,3,2,1,1,8,6,5,4,3,3,
%T A138029 3,2,2,2,2,3,3,3,4,4,5,6,8,1,1,1,2,3,4,6,9,1,2,3,5,8,1,2,3,6,1,1,3,5,
%U A138029 1,2,3,7,1,2,5,1,2,4,1,2,4,1,2,5,1,2,6,1,3,8,2,5,1,3,8,2,5,1,3,1,2,7,2,5,1
%N A138029 Main diagonal of A138028; the most significant digit of n^(n-1).
%H A138029 Robert Israel, <a href="/A138029/b138029.txt">Table of n, a(n) for n = 1..10000</a>
%p A138029 f:= n -> floor(10^frac((n-1)*log[10](n))):
%p A138029 map(f, [$1..200]); # _Robert Israel_, Jan 15 2019
%t A138029 f[n_, k_] := Quotient[n^k, 10^Floor[k*Log[10, n]]]; Table[ f[ n, n - 1], {n, 105}]
%Y A138029 Cf. A061505, A138028.
%K A138029 base,nonn
%O A138029 1,2
%A A138029 _Robert G. Wilson v_, Feb 10 2008
%E A138029 Name corrected by _Robert Israel_, Jan 15 2019