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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.

A191834 Numbers n not divisible by 2 or 3 such that k^k == k+1 (mod n) has no nonzero solutions.

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%I A191834 #17 Aug 11 2015 00:00:33
%S A191834 205,301,455,1015,1025,1085,1435,1505,2107,2255,2275,2485,2665,3185,
%T A191834 3311,3485,3895,3913,4715,4823,5005,5075,5117,5125,5425,5467,5719,
%U A191834 5915,5945,6355,6923,7105,7175,7525,7585,7595,7735,8405,8645,8729,8815,9331,9635,10045,10465,10535,10865,11137,11165,11275,11375,11935,12095
%N A191834 Numbers n not divisible by 2 or 3 such that k^k == k+1 (mod n) has no nonzero solutions.
%C A191834 Values of A007310(n) for n such that A191833(n) = 0.
%C A191834 This sequence contains no primes. If p is a prime, and r is a primitive root of p, the numbers (r+j*p)^(r+j*p) for j = 1..p-1 include all residues of units mod p, and for p > 3, r+1 must be a unit.
%C A191834 The complete list of n such that k^k == k+1 (mod n) has no nonzero solutions is the union of A047229 and this sequence.
%H A191834 Jean-François Alcover, <a href="/A191834/b191834.txt">Table of n, a(n) for n = 1..150</a>
%t A191834 A191833[n_] := (For[m = 2*n + 2*Floor[n/2] - 1; k = 1, k <= m^2, k++, If[PowerMod[k, k, m] == Mod[k+1, m], Return[{k, m}]]]; {0, m}); Reap[For[j = 1; n = 1, n <= 5000, n++, {z, m} = A191833[n]; If[z == 0, Print["a(", j++, ") = ", m]; Sow[m]]]][[2, 1]] (* _Jean-François Alcover_, Sep 13 2013 *)
%Y A191834 Cf. A191833, A191835 (primitive elements).
%K A191834 nonn
%O A191834 1,1
%A A191834 _Franklin T. Adams-Watters_, Jun 17 2011
%E A191834 Terms a(30) onward from _Max Alekseyev_, Sep 10 2013