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A250356 Number of length 7 arrays x(i), i=1..7 with x(i) in i..i+n and no value appearing more than 2 times 1

%I

%S 128,1791,12620,59406,214716,644040,1681860,3932472,8409252,16713576,

%T 31259100,55546440,94493292,154825032,245530836,378390360,568576020,

%U 835335912,1202762412,1700651496,2365457820,3241350600,4381375332

%N Number of length 7 arrays x(i), i=1..7 with x(i) in i..i+n and no value appearing more than 2 times

%C Row 7 of A250351

%H R. H. Hardin, <a href="/A250356/b250356.txt">Table of n, a(n) for n = 1..91</a>

%F Empirical: a(n) = n^7 + 7*n^6 - 14*n^5 + 105*n^4 + 105*n^3 - 532*n^2 + 1252*n - 744 for n>4

%e Some solutions for n=4

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

%e ..3....3....1....1....3....2....4....1....4....1....2....2....3....5....4....2

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 19 2014

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Last modified October 20 22:44 EDT 2019. Contains 328291 sequences. (Running on oeis4.)