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%I #25 Dec 18 2019 00:32:40
%S 1007749,18791108,-186878195,-1050017609,-9619142907,-4098030816,
%T -59235488169,-43035664380,-25214990766,-189627605493,779029018560,
%U 14532890711040,364989611366055,1929185790836472,-1121729573175075,13492031465869425,329600773788765624
%N Circulant determinant chain starting at 1007749
%C 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 If we had started at 247, the next term in the chain, and all subsequent terms, would be 247, since (see A219324)
%C ..........| 2 4 7 |
%C 247 = det | 7 2 4 |. - _N. J. A. Sloane_, Dec 18 2019
%C ..........| 4 7 2 |
%H 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 N. J. A. Sloane, <a href="http://neilsloane.com/doc/sampler2.pdf">Recent and Noteworthy Sequences in the OEIS</a>, Dec. 18, 2012
%Y Cf. A219324.
%K sign,base
%O 1,1
%A _Jeff Heleen_, Dec 17 2019