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%I #19 Mar 12 2017 16:48:08
%S 1,2,6,15,42,99,262,633,1592,3897,9697,23767,58804,144541
%N Number of irreducible matrices X of all sizes with nonnegative integral entries satisfying X^2 = nX.
%H Jakob Zimmermann, <a href="http://arxiv.org/abs/1701.03699">Counting quasi-idempotent irreducible integral matrices</a>, arXiv:1701.03699 [math.CO], 2017.
%Y Cf. A280783.
%K nonn,more
%O 1,2
%A _N. J. A. Sloane_, Jan 20 2017
%E Definition corrected by _N. J. A. Sloane_, Jan 23 2017 at the suggestion of _Jakob Zimmermann_
%E a(14) from _Jakob Zimmermann_, Jan 23 2017