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A202967 Number of arrays of 7 integers in -n..n with sum zero and adjacent elements differing in absolute value 1

%I

%S 6,524,9872,66208,289536,941086,2537024,5933492,12515772,24295760,

%T 44188086,76110890,125357152,198686606,304811136,454458544,660981870,

%U 940393644,1312104510,1798910920,2427885688,3230300850,4242680088

%N Number of arrays of 7 integers in -n..n with sum zero and adjacent elements differing in absolute value

%C Row 5 of A202962

%H R. H. Hardin, <a href="/A202967/b202967.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -2*a(n-5) +a(n-6) -3*a(n-7) +3*a(n-8) -a(n-9) +2*a(n-10) +a(n-11) -a(n-13) -2*a(n-14) +a(n-15) -3*a(n-16) +3*a(n-17) -a(n-18) +2*a(n-19) -a(n-21) +a(n-22) -2*a(n-23) +a(n-24)

%e Some solutions for n=4

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

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

%e ..4...-1....0...-4...-2...-1....1....0...-4....4...-4....1...-2...-1....4...-4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Dec 26 2011

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Last modified May 28 09:09 EDT 2022. Contains 354112 sequences. (Running on oeis4.)