cp's OEIS Frontend

A187990 Number of nondecreasing arrangements of 6 numbers x(i) in -(n+4)..(n+4) with the sum of sign(x(i))*2^|x(i)| zero.

%I A187990 #34 Sep 18 2024 06:56:08
%S A187990 67,117,181,260,355,467,597,746,915,1105,1317,1552,1811,2095,2405,
%T A187990 2742,3107,3501,3925,4380,4867,5387,5941,6530,7155,7817,8517,9256,
%U A187990 10035,10855,11717,12622,13571,14565,15605,16692,17827,19011,20245,21530,22867,24257
%N A187990 Number of nondecreasing arrangements of 6 numbers x(i) in -(n+4)..(n+4) with the sum of sign(x(i))*2^|x(i)| zero.
%H A187990 Manuel Kauers and Christoph Koutschan, <a href="/A187990/b187990.txt">Table of n, a(n) for n = 0..1000</a> (terms 1..50 from R. H. Hardin).
%H A187990 M. Kauers and C. Koutschan, <a href="https://arxiv.org/abs/2303.02793">Some D-finite and some possibly D-finite sequences in the OEIS</a>, arXiv:2303.02793 [cs.SC], 2023.
%H A187990 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A187990 a(n) = (n^3 + 39*n^2 + 260*n + 402)/6. - _Manuel Kauers_ and _Christoph Koutschan_, Mar 01 2023
%F A187990 G.f.: -(-67+151*x-115*x^2+30*x^3)/(x-1)^4. - _R. J. Mathar_, Apr 30 2023
%e A187990 Some solutions for n=3
%e A187990  -2   -5   -6   -5   -7   -6   -4   -4   -6   -5   -7   -6   -3   -6   -3   -7
%e A187990  -1   -4   -5   -1   -6   -3   -3   -2   -6   -4   -3   -6   -3   -3   -3   -5
%e A187990   0   -4    4   -1    5   -2   -3   -1   -5   -1    1    5   -3   -3   -2   -3
%e A187990   0    4    4    2    5   -2   -1   -1    4    1    1    5    2    3    1    3
%e A187990   1    4    5    4    6    4    1    3    4    4    2    5    2    3    1    5
%e A187990   1    5    5    4    6    6    5    4    7    5    7    5    4    6    4    7
%Y A187990 Row 6 of A187988.
%K A187990 nonn,easy
%O A187990 0,1
%A A187990 _R. H. Hardin_, Mar 18 2011
%E A187990 a(27) corrected by _Manuel Kauers_ and _Christoph Koutschan_, Mar 01 2023