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 A127821 #59 Dec 16 2024 14:52:50
%S A127821 2,11,5,51,44,7,15,371285,10,74853,158,13757837,17,5805311,22,2181,38,
%T A127821 25,30,9667,74,87,146,23441,88,19629779,35,45,70,235433,46,55,34,309,
%U A127821 134
%N A127821 a(n) = least k such that the remainder of 13^k divided by k is n.
%C A127821 a(36) > 10^16. - _Max Alekseyev_, Oct 25 2016
%H A127821 Fausto A. C. Cariboni, <a href="/A127821/a127821_3.txt">Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found</a>, Oct 31 2016 [With 207 new terms, this supersedes the earlier table from Robert G. Wilson v et al.]
%H A127821 Doug Strain, <a href="/A127821/a127821_5.txt">Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found</a>, [With more terms, this supersedes the earlier table from Fausto A. C. Cariboni and Robert G. Wilson v et al.]
%H A127821 Robert G. Wilson v et al., <a href="/A127821/a127821_1.txt">Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found</a>, Feb 06 2007; Nov 30 2010.
%t A127821 t = Table[0, {10000} ]; k = 1; While[ k < 3500000000, a = PowerMod[13, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t
%Y A127821 Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820.
%K A127821 nonn,hard,more
%O A127821 1,1
%A A127821 _Alexander Adamchuk_, Jan 30 2007
%E A127821 More terms from _Robert G. Wilson v_, Feb 06 2007
%E A127821 a(264), a(798), a(884), a(896), a(976), a(980), a(152), a(171), a(296), a(464), a(824), a(870) from _Daniel Morel_, Jun 17, Nov 30 2010