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A307887 Least number k such that the determinant of the symmetric Toeplitz matrix formed by its decimal digits is equal to n.

%I A307887 #13 May 03 2019 15:42:08
%S A307887 0,1,2,3,4,5,6,7,8,9,433,65,42,76,455,41,40,98,457,766,64,52,243,788,
%T A307887 51,50,413,63,86,142,21024,3055,62,74,645,61,60,524,25624,85,73,756,
%U A307887 20031,514,412,72,23688,152,71,70,641,364,355,2542,245,83,95,798,625
%N A307887 Least number k such that the determinant of the symmetric Toeplitz matrix formed by its decimal digits is equal to n.
%H A307887 Rémy Sigrist, <a href="/A307887/b307887.txt">Table of n, a(n) for n = 0..10000</a>
%H A307887 Wikipedia, <a href="https://en.wikipedia.org/wiki/Toeplitz_matrix">Toeplitz matrix</a>
%e A307887                         | 4 3 3 |
%e A307887 a(10) = 433 because det | 3 4 3 | = 10.
%e A307887                         | 3 3 4 |
%e A307887 .
%e A307887                          | 2 5 6 2 4 |
%e A307887                          | 5 2 5 6 2 |
%e A307887 a(38)= 25624 because det | 6 5 2 5 6 | = 38.
%e A307887                          | 2 6 5 2 5 |
%e A307887                          | 4 2 6 5 2 |
%p A307887 with(numtheory): with(linalg): P:=proc(q) local a,c,i,k,n; print(0);
%p A307887 for i from 1 to q do for n from 1 to q do a:=convert(n,base,10):
%p A307887 c:=[]: for k from 1 to nops(a) do c:=[op(c), a[-k]]: od:
%p A307887 if det(toeplitz(c))=i then print(n); break: fi: od: od: end: P(10^6);
%Y A307887 Cf. A306593.
%K A307887 nonn,base
%O A307887 0,3
%A A307887 _Paolo P. Lava_, May 03 2019