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A250349 Number of length n arrays x(i), i=1..n with x(i) in i..i+6 and no value appearing more than 2 times.

%I A250349 #6 Jul 23 2025 12:19:57
%S A250349 7,49,338,2287,15186,99344,644040,4164930,26882466,173276640,
%T A250349 1115910270,7182799173,46220503936,297376327082,1913081363032,
%U A250349 12306454081360,79161863609011,509201240096045,3275346169991511,21067913854706817
%N A250349 Number of length n arrays x(i), i=1..n with x(i) in i..i+6 and no value appearing more than 2 times.
%C A250349 Column 6 of A250351
%H A250349 R. H. Hardin, <a href="/A250349/b250349.txt">Table of n, a(n) for n = 1..210</a>
%F A250349 Empirical: a(n) = 7*a(n-1) -12*a(n-3) -32*a(n-4) -101*a(n-5) -623*a(n-6) -3703*a(n-7) +2630*a(n-8) +10358*a(n-9) +15805*a(n-10) +19448*a(n-11) +41930*a(n-12) +17560*a(n-13) -133023*a(n-14) -179079*a(n-15) -42337*a(n-16) +101951*a(n-17) -34974*a(n-18) -21497*a(n-19) +198775*a(n-20) +430980*a(n-21) +205427*a(n-22) -195761*a(n-23) -191518*a(n-24) -100666*a(n-25) -82593*a(n-26) -182721*a(n-27) -26175*a(n-28) +61736*a(n-29) +73291*a(n-30) +56839*a(n-31) -14702*a(n-32) -18860*a(n-33) -26635*a(n-34) -3079*a(n-35) +4310*a(n-36) +5890*a(n-37) -1330*a(n-38) -882*a(n-39) +37*a(n-40) -321*a(n-41) -191*a(n-42) +119*a(n-43) +25*a(n-44) -9*a(n-45) -a(n-46) -a(n-48)
%e A250349 Some solutions for n=6
%e A250349 ..1....2....2....1....0....1....4....2....3....4....3....1....2....2....0....4
%e A250349 ..4....3....4....1....3....1....5....7....2....7....5....3....2....2....6....7
%e A250349 ..8....3....7....3....5....5....2....4....5....3....6....4....7....4....2....3
%e A250349 ..7....9....7....8....5....7....9....6....9....4....7....5....5....4....6....9
%e A250349 .10....7....6....4...10....9...10....4....6....8...10....9....8....6....7....6
%e A250349 ..8....8...10....5....6....9....5...11....6....9....8....8....5....8....8....9
%K A250349 nonn
%O A250349 1,1
%A A250349 _R. H. Hardin_, Nov 19 2014