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A250365 Number of length 7 arrays x(i), i=1..7 with x(i) in i..i+n and no value appearing more than 3 times 1

%I #4 Nov 19 2014 16:04:37

%S 128,2187,16128,76300,272760,803382,2052904,4698744,9854280,19251970,

%T 35471832,62220324,104664664,169827630,267047880,408510832,609855144,

%U 890859834,1276217080,1796395740,2488600632,3397832614,4578054504

%N Number of length 7 arrays x(i), i=1..7 with x(i) in i..i+n and no value appearing more than 3 times

%C Row 7 of A250361

%H R. H. Hardin, <a href="/A250365/b250365.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = n^7 + 7*n^6 + 21*n^5 + 147*n^3 + 49*n^2 + 7*n for n>4

%e Some solutions for n=4

%e ..4....3....2....2....1....2....1....0....2....3....3....1....0....1....4....4

%e ..4....5....4....2....5....2....1....2....5....1....2....2....5....2....4....5

%e ..3....3....6....4....6....2....2....5....4....2....2....6....6....3....4....4

%e ..5....7....6....5....3....4....7....3....6....6....6....6....7....6....3....7

%e ..4....8....4....5....5....8....7....5....4....8....7....8....4....8....5....6

%e ..6....7....5....7....5....6....9....8....9....8....9....7....5....9....9....5

%e ..6....7....7....7....7....9....9....8....8...10....6...10...10....7....8....8

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 19 2014

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Last modified March 3 11:07 EST 2024. Contains 370511 sequences. (Running on oeis4.)