%I #25 Mar 05 2019 16:24:55
%S 12613,15737,43189,56263,72337,76289,77783,84067,102559,108179,109789,
%T 109843,109891,115727,115901,120557,125927,127247,135613,149287,
%U 155599,161461,169843,172973,178307,179233,184559,188519,192271,198461,206489,218833,220793,221671
%N Irregular primes with irregularity index four.
%H Amiram Eldar, <a href="/A219332/b219332.txt">Table of n, a(n) for n = 1..10000</a> (calculated by Hart et al., terms 1..1282 from T. D. Noe, calculated by Buhler et al.)
%H J. Buhler, R. Crandall, R. Ernvall, T. Metsankyla and M. A. Shokrollahi, <a href="http://dx.doi.org/10.1006/jsco.1999.1011">Irregular Primes and Cyclotomic Invariants to 12 Million</a>, J. Symbolic Computation 31, 2001, 89-96.
%H William Hart, David Harvey and Wilson Ong, <a href="https://doi.org/10.1090/mcom/3211">Irregular primes to two billion</a>, Mathematics of Computation, Vol. 86, No. 308 (2017), pp. 3031-3049; also available at <a href="https://arxiv.org/abs/1605.02398">arXiv:1605.02398 [math.NT]</a>, 2016.
%H David Harvey, <a href="https://web.maths.unsw.edu.au/~davidharvey/papers/twobillion/">Irregular primes to two billion</a> (includes a list of all primes less than 2^31).
%Y Cf. A061576, A007703, A000928, A073276, A073277, A060975, A219333, A219334, A219335.
%K nonn
%O 1,1
%A _Robert G. Wilson v_, Nov 18 2012