cp's OEIS Frontend

A246888 Number of length n+4 0..4 arrays with some pair in every consecutive five terms totalling exactly 4.

%I A246888 #6 Jun 02 2025 10:14:25
%S A246888 2701,12481,57585,264981,1216081,5592169,25710385,118192273,543322645,
%T A246888 2497751105,11482493485,52786380721,242665353541,1115563238521,
%U A246888 5128382983861,23575813154485,108380944031221,498240685840957
%N A246888 Number of length n+4 0..4 arrays with some pair in every consecutive five terms totalling exactly 4.
%C A246888 Column 4 of A246892
%H A246888 R. H. Hardin, <a href="/A246888/b246888.txt">Table of n, a(n) for n = 1..210</a>
%F A246888 Empirical: a(n) = 3*a(n-1) +6*a(n-2) +5*a(n-3) +17*a(n-4) -16*a(n-5) -117*a(n-6) -174*a(n-7) -295*a(n-8) -478*a(n-9) +437*a(n-10) +1237*a(n-11) +663*a(n-12) +1581*a(n-13) +2542*a(n-14) -1551*a(n-15) -2164*a(n-16) -1754*a(n-17) -1473*a(n-18) +623*a(n-19) +1190*a(n-20) +651*a(n-21) +184*a(n-22) -263*a(n-23) -141*a(n-24) -109*a(n-25) -11*a(n-26) +46*a(n-27) +9*a(n-28) +10*a(n-29) +2*a(n-30) -3*a(n-31)
%e A246888 Some solutions for n=3
%e A246888 ..4....4....4....1....4....4....1....4....4....1....4....4....0....3....3....2
%e A246888 ..3....4....3....0....4....3....1....1....4....1....3....4....2....1....2....3
%e A246888 ..2....4....1....1....3....0....4....4....2....4....4....0....0....2....3....2
%e A246888 ..2....3....4....2....0....4....3....2....1....3....2....1....4....4....1....4
%e A246888 ..3....0....0....2....4....2....1....2....2....4....1....0....3....1....3....1
%e A246888 ..0....0....3....2....0....0....3....3....3....2....1....4....0....2....4....0
%e A246888 ..3....2....0....4....3....0....3....4....1....0....0....0....2....1....1....4
%K A246888 nonn
%O A246888 1,1
%A A246888 _R. H. Hardin_, Sep 06 2014