cp's OEIS Frontend

A219327 Positive integers k that are equal to the absolute value of the determinant of the circulant matrix formed by the decimal digits of k.

%I A219327 #33 Oct 19 2021 02:50:45
%S A219327 1,2,3,4,5,6,7,8,9,48,247,370,378,407,481,518,592,629,1360,1547,3075,
%T A219327 26027,26933,45018,69781,80487,123823,154791,289835,1920261,2137616,
%U A219327 2716713,3100883,3480140,3934896,4179451,4830936,5218958,11955168,23203827,80651025,95738203
%N A219327 Positive integers k that are equal to the absolute value of the determinant of the circulant matrix formed by the decimal digits of k.
%C A219327 Contains A219324 and A219326 as subsequences.
%C A219327 Equal to the sequence defined by replacing circulant matrices with left circulant matrices. - _Chai Wah Wu_, Oct 18 2021
%H A219327 Robert G. Wilson v and Max Alekseyev, <a href="/A219327/b219327.txt">Table of n, a(n) for n = 1..63</a> (complete up to 10^10)
%o A219327 (Python)
%o A219327 from sympy import Matrix
%o A219327 A219327_list = []
%o A219327 for n in range(1,10**6):
%o A219327     s = [int(d) for d in str(n)]
%o A219327     m = len(s)
%o A219327     if n == abs(Matrix(m, m, lambda i, j: s[(i-j) % m]).det()):
%o A219327         A219327_list.append(n) # _Chai Wah Wu_, Oct 18 2021
%Y A219327 A219324, the main entry for this sequence, provides references and further details.
%Y A219327 Cf. A219326.
%K A219327 base,nonn
%O A219327 1,2
%A A219327 _Max Alekseyev_, Nov 17 2012
%E A219327 a(53)-a(63) from _Max Alekseyev_, Feb 15 2013