cp's OEIS Frontend

A260031 Final nonzero digit of n^n in base 12.

%I A260031 #21 Apr 06 2020 02:43:56
%S A260031 1,4,3,4,5,3,7,4,9,4,11,1,1,4,3,4,5,3,7,4,9,4,11,4,1,4,3,4,5,3,7,4,9,
%T A260031 4,11,9,1,4,3,4,5,3,7,4,9,4,11,4,1,4,3,4,5,3,7,4,9,4,11,1,1,4,3,4,5,3,
%U A260031 7,4,9,4,11,9,1,4,3,4,5,3,7,4,9,4,11,1
%N A260031 Final nonzero digit of n^n in base 12.
%H A260031 Chai Wah Wu, <a href="/A260031/b260031.txt">Table of n, a(n) for n = 1..10000</a>
%H A260031 José María Grau and Antonio M. Oller-Marcén, <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 preprint arXiv:1203.4066 [math.NT], 2012.
%o A260031 (Python)
%o A260031 from gmpy2 import mpz, digits
%o A260031 def A260031(n):
%o A260031     s = digits(mpz(n)**mpz(n),12)
%o A260031     t = s[-1]
%o A260031     while t == '0':
%o A260031         s = s[:-1]
%o A260031         t = s[-1]
%o A260031     return int(t,12) # _Chai Wah Wu_, Jul 19 2015
%o A260031 (Haskell)
%o A260031 import Math.NumberTheory.Moduli (powerMod)
%o A260031 a260031 n = if x > 0 then x else f $ div (n ^ n) 12
%o A260031           where x = powerMod n n 12
%o A260031                 f z = if m == 0 then f z' else m
%o A260031                       where (z', m) = divMod z 12
%o A260031 -- _Reinhard Zumkeller_, Jul 19 2015
%Y A260031 Cf. A174824, A204819, A230024.
%Y A260031 Cf. A000312, A010881.
%K A260031 nonn
%O A260031 1,2
%A A260031 _N. J. A. Sloane_, Jul 19 2015
%E A260031 More terms from _Chai Wah Wu_, Jul 19 2015