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.

A267230 Number of length-n 0..6 arrays with no following elements greater than or equal to the first repeated value.

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%I A267230 #9 Feb 06 2018 04:16:47
%S A267230 7,49,315,1981,12327,76237,469623,2884909,17686215,108259885,
%T A267230 661872471,4042575277,24671450343,150466937773,917151735159,
%U A267230 5587651325485,34027698639111,207144227712301,1260572274312087,7668877406965933
%N A267230 Number of length-n 0..6 arrays with no following elements greater than or equal to the first repeated value.
%C A267230 Column 6 of A267232.
%H A267230 R. H. Hardin, <a href="/A267230/b267230.txt">Table of n, a(n) for n = 1..210</a>
%F A267230 Empirical: a(n) = 27*a(n-1) - 301*a(n-2) + 1785*a(n-3) - 6034*a(n-4) + 11508*a(n-5) - 11304*a(n-6) + 4320*a(n-7) for n > 8.
%F A267230 Conjectures from _Colin Barker_, Feb 05 2018: (Start)
%F A267230 G.f.: x*(7 - 140*x + 1099*x^2 - 4270*x^3 + 8428*x^4 - 7476*x^5 + 1512*x^6 + 720*x^7) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)*(1 - 6*x)^2).
%F A267230 a(n) = (-45*2^n - 40*3^n - 45*4^n - 72*5^n + 557*6^n + 5*2^(1 + n)*3^n*n - 72) / 360 for n>1.
%F A267230 (End)
%e A267230 Some solutions for n=6:
%e A267230   3  2  1  3  1  2  2  0  4  0  2  0  1  3  6  3
%e A267230   6  6  0  6  2  3  3  3  5  2  4  1  5  4  5  6
%e A267230   2  1  3  1  0  5  5  2  2  6  3  0  3  1  5  4
%e A267230   5  3  6  3  4  6  2  5  4  4  1  4  0  4  2  2
%e A267230   2  1  1  4  1  5  0  1  5  0  6  6  3  2  4  0
%e A267230   3  0  6  0  1  2  4  1  2  0  6  6  1  4  0  6
%Y A267230 Cf. A267232.
%K A267230 nonn
%O A267230 1,1
%A A267230 _R. H. Hardin_, Jan 12 2016