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 A230024 #33 Oct 02 2024 17:13:55
%S A230024 1,4,11,1,5,4,7,1,9,4,3,1,13,4,15,1,1,4,11,1,5,4,7,1,9,4,3,1,13,4,15,
%T A230024 1,1,4,11,1,5,4,7,1,9,4,3,1,13,4,15,1,1,4,11,1,5,4,7,1,9,4,3,1,13,4,
%U A230024 15,1,1,4,11,1,5,4,7,1,9,4,3,1,13,4,15,1,1
%N A230024 Final nonzero digit of n^n in base 16.
%C A230024 The sequence is periodic with period length 16.
%H A230024 Jose María Grau and A. M. Oller-Marcen, <a href="http://arxiv.org/abs/1203.4066">On the last digit and the last non-zero digit of n^n in base b</a>, arXiv:1203.4066 [math.NT], 2012.
%H A230024 Jose María Grau and A. M. Oller-Marcen, <a href="http://pdf.medrang.co.kr/kms01/BKMS/51/BKMS-51-5-1325-1337.pdf">On the last digit and the last non-zero digit of n^n in base b</a>, Bull. Korean Math. Soc. 51 (2014), No. 5, pp. 1325-1337.
%t A230024 f[n_, b_] := Module[{m = n^n}, While[Mod[m, b] == 0, m = m/b]; Mod[m, b]]; y = Table[f[i, 16], {i, 1, 100}]
%t A230024 Table[Drop[IntegerDigits[n^n,16],-IntegerExponent[n^n,16]][[-1]],{n,100}] (* or *) PadRight[{},100,{1,4,11,1,5,4,7,1,9,4,3,1,13,4,15,1}] (* _Harvey P. Dale_, Oct 02 2024 *)
%Y A230024 Cf. A116081, A204815-A204819, A230024, A204697.
%K A230024 nonn,base
%O A230024 1,2
%A A230024 _José María Grau Ribas_, Feb 23 2014