cp's OEIS Frontend

A166769 Number of n X 5 1..2 arrays containing at least one of each value, and all equal values connected.

%I A166769 #9 Dec 12 2024 14:53:41
%S A166769 8,90,712,4942,32426,206392,1284728,7855758,47333834,281703020,
%T A166769 1659086104,9684388606,56098465446,322820680276,1847076802248,
%U A166769 10515831592642,59608838934806,336604310563828,1894399026364292,10630153480987994,59494181482941446,332206086480550664
%N A166769 Number of n X 5 1..2 arrays containing at least one of each value, and all equal values connected.
%H A166769 Andrew Howroyd, <a href="/A166769/b166769.txt">Table of n, a(n) for n = 1..500</a>
%H A166769 <a href="/index/Rec#order_18">Index entries for linear recurrences with constant coefficients</a>, signature (24,-245,1403,-5022,11858, -18861,19829,-12118,1011,5487, -4942,1470,543,-565,78,67,-12,-4).
%F A166769 G.f.: 2*x*(4 - 51*x + 256*x^2 - 660*x^3 + 1082*x^4 - 1431*x^5 + 698*x^6 + 4667*x^7 - 15736*x^8 + 23396*x^9 - 16421*x^10 + 1174*x^11 + 4664*x^12 - 1000*x^13 - 500*x^14 + 100*x^15 - 221*x^16 - 99*x^17 - 10*x^18)/((1 - x)^2*(1 - 7*x + 12*x^2 - 7*x^3 + 3*x^4 + 2*x^5)^2*(1 - 8*x + 15*x^2 - 5*x^3 - 9*x^4 + 2*x^5 + x^6)). - _Andrew Howroyd_, Dec 12 2024
%e A166769 Some solutions for n=4
%e A166769 ...1.1.1.2.2...1.1.1.2.2...1.1.1.1.1...2.2.2.2.1...1.1.1.2.2...1.1.1.2.2
%e A166769 ...1.1.1.1.2...1.2.2.2.1...1.2.1.1.1...2.2.1.1.1...1.2.1.1.2...1.1.1.1.2
%e A166769 ...1.2.2.2.2...1.1.1.2.1...1.2.1.2.1...2.1.1.1.1...1.2.1.1.2...1.1.1.1.2
%e A166769 ...1.1.1.1.2...1.1.1.1.1...1.2.2.2.2...2.2.2.2.2...1.2.2.2.2...1.1.1.1.1
%e A166769 ------
%e A166769 ...1.1.1.1.2...2.2.2.2.2...1.1.1.1.1...1.1.2.2.2...1.1.1.2.2...1.1.1.1.1
%e A166769 ...2.2.2.1.2...1.1.1.1.2...2.2.2.2.1...1.2.2.2.2...1.1.1.1.2...1.2.1.1.1
%e A166769 ...2.2.2.2.2...2.2.2.2.2...1.1.1.2.1...1.2.2.1.1...1.1.1.2.2...2.2.1.1.2
%e A166769 ...2.2.2.2.2...2.2.2.2.2...1.1.1.1.1...1.1.1.1.1...1.1.1.2.2...2.2.2.2.2
%Y A166769 Twice row 5 of A378932.
%K A166769 nonn
%O A166769 1,1
%A A166769 _R. H. Hardin_, Oct 21 2009
%E A166769 a(10) onwards from _Andrew Howroyd_, Dec 12 2024