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%I A330519 #25 Dec 18 2019 00:32:40
%S A330519 1007749,18791108,-186878195,-1050017609,-9619142907,-4098030816,
%T A330519 -59235488169,-43035664380,-25214990766,-189627605493,779029018560,
%U A330519 14532890711040,364989611366055,1929185790836472,-1121729573175075,13492031465869425,329600773788765624
%N A330519 Circulant determinant chain starting at 1007749
%C A330519 Form a circulant matrix from a given number. Find the determinant. Use that determinant to form the next circulant matrix. Repeat. If a determinant is negative, multiply each element of the next matrix by -1. 1007749 is the smallest number whose chain appears to increase without bound. (It would be nice to have a proof that this chain is unbounded!)
%C A330519 If we had started at 247, the next term in the chain, and all subsequent terms, would be 247, since (see A219324)
%C A330519 ..........| 2 4 7 |
%C A330519 247 = det | 7 2 4 |. - _N. J. A. Sloane_, Dec 18 2019
%C A330519 ..........| 4 7 2 |
%H A330519 Jeff Heleen, <a href="/A330519/b330519.txt">Circulant determinant chain for 1007749: gives table of n, a(n) for n from 1 to 36.</a>
%H A330519 N. J. A. Sloane, <a href="http://neilsloane.com/doc/sampler2.pdf">Recent and Noteworthy Sequences in the OEIS</a>, Dec. 18, 2012
%Y A330519 Cf. A219324.
%K A330519 sign,base
%O A330519 1,1
%A A330519 _Jeff Heleen_, Dec 17 2019

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