%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