cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A290540 Determinant of circulant matrix of order 10 with entries in the first row that are (-1)^(j-1)*Sum_{k>=0} (-1)^k*binomial(n, 10*k+j-1), for j=1..10.

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%I A290540 #36 Aug 10 2018 02:36:51
%S A290540 1,0,0,0,0,0,0,0,0,0,-2276485387658524,-523547340003805770400,
%T A290540 -39617190432735671861429500,-2896792542975174202888623380000,
%U A290540 -95819032881785191861991031568287500,-1018409199709889673458815786392849200000
%N A290540 Determinant of circulant matrix of order 10 with entries in the first row that are (-1)^(j-1)*Sum_{k>=0} (-1)^k*binomial(n, 10*k+j-1), for j=1..10.
%C A290540 a(n) = 0 for n == 9 (mod 10).
%C A290540 A generalization. For an even N >= 2, consider the determinant of circulant matrix of order N with entries in the first row (-1)^(j-1)K_j(n), j=1..N, where K_j(n) = Sum_{k>=0} (-1)^k*binomial(n, N*k+j-1). Then it is 0 for n == N-1 (mod N). This statement follows from an easily proved identity K_j(N*t + N - 1) = (-1)^t*K_(N - j + 1)(N*t + N - 1) and a known calculation formula for the determinant of circulant matrix [Wikipedia]. Besides, it is 0 for n=1..N-2. We also conjecture that every such sequence contains infinitely many blocks of N-1 negative and N-1 positive terms separated by 0's.
%H A290540 Vladimir Shevelev, <a href="https://arxiv.org/abs/1706.01454">Combinatorial identities generated by difference analogs of hyperbolic and trigonometric functions of order n</a>, arXiv:1706.01454 [math.CO], 2017.
%H A290540 Wikipedia, <a href="https://en.wikipedia.org/wiki/Circulant_matrix">Circulant matrix</a>
%p A290540 f:= n -> LinearAlgebra:-Determinant(Matrix(10,10,shape=
%p A290540   Circulant[seq((-1)^j*add((-1)^k*binomial(n,10*k+j),
%p A290540      k=0..(n-j)/10), j=0..9)])):
%p A290540 map(f, [$0..20]); # _Robert Israel_, Aug 08 2017
%t A290540 ro[n_] := Table[(-1)^(j-1) Sum[(-1)^k Binomial[n, 10k+j-1], {k, 0, n/10}], {j, 1, 10}];
%t A290540 M[n_] := Table[RotateRight[ro[n], m], {m, 0, 9}];
%t A290540 a[n_] := Det[M[n]];
%t A290540 Table[a[n], {n, 0, 15}] (* _Jean-François Alcover_, Aug 10 2018 *)
%Y A290540 Cf. A290286, A290535, A290539.
%K A290540 sign
%O A290540 0,11
%A A290540 _Vladimir Shevelev_ and _Peter J. C. Moses_, Aug 05 2017