cp's OEIS Frontend

A219326 Positive integers m that are equal to the determinant of the circulant matrix formed by the decimal digits of m in reverse order.

%I A219326 #20 Oct 18 2021 15:19:28
%S A219326 1,2,3,4,5,6,7,8,9,48,247,370,378,407,481,518,592,629,1547,26027,
%T A219326 26933,45018,69781,80487,123823,289835,1920261,2137616,2716713,
%U A219326 3100883,3480140,3934896,4179451,4830936,5218958,23203827
%N A219326 Positive integers m that are equal to the determinant of the circulant matrix formed by the decimal digits of m in reverse order.
%C A219326 Terms with odd number of digits are the same as in A219324.
%H A219326 Max Alekseyev, <a href="/A219326/b219326.txt">Table of n, a(n) for n = 1..53</a> (complete up to 10^10)
%e A219326            | 7 4 5 1 |
%e A219326 1547 = det | 1 7 4 5 |
%e A219326            | 5 1 7 4 |
%e A219326            | 4 5 1 7 |
%o A219326 (Python)
%o A219326 from sympy import Matrix
%o A219326 A219326_list = []
%o A219326 for n in range(1,10**6):
%o A219326     s = [int(d) for d in str(n)][::-1]
%o A219326     m = len(s)
%o A219326     if n == Matrix(m, m, lambda i, j: s[(i-j) % m]).det():
%o A219326         A219326_list.append(n) # _Chai Wah Wu_, Oct 18 2021
%Y A219326 A219324 is the main entry for this sequence, provides references and further details.
%K A219326 base,nonn
%O A219326 1,2
%A A219326 _Max Alekseyev_, Nov 17 2012