OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Circulant Matrix.
Wikipedia, Circulant matrix.
EXAMPLE
det | 1 | = 1 = 1*1.
.
| 1 0 1 6 8|
| 8 1 0 1 6|
det | 6 8 1 0 1| = 20336 = 2*10168.
| 1 6 8 1 0|
| 0 1 6 8 1|
MAPLE
with(linalg): P:=proc(q) local a, b, c, d, i, j, k, n, t;
for i from 1 to q do for n from 1 to q do
d:=ilog10(n)+1; a:=convert(n, base, 10); c:=[];
for k from 1 to nops(a) do c:=[op(c), a[-k]]; od; t:=[op([]), c];
for k from 2 to d do b:=[op([]), c[nops(c)]]; for j from 1 to nops(c)-1 do
b:=[op(b), c[j]]; od; c:=b; t:=[op(t), c]; od; if i*n=det(t) then
print(n); break; fi; od; od; end: P(10^7);
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Paolo P. Lava, Jan 17 2019
EXTENSIONS
a(6)-a(17) from Giovanni Resta, Jan 21 2019
STATUS
approved