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%I #7 Mar 08 2023 13:28:17
%S 169,5089,50391,286207,1150785,3681179,9975741,23891417,51927841,
%T 104482217,197273691,353343429,605118809,997367601,1589978367,
%U 2462102871,3715701055,5481137105,7921503361,11239970929,15684870457,21559136673
%N Number of -n..n arrays of 7 elements with first and second differences also in -n..n.
%C Row 7 of A201088.
%H R. H. Hardin, <a href="/A201092/b201092.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = -a(n-1) +a(n-2) +3*a(n-3) +4*a(n-4) +2*a(n-5) -2*a(n-6) -8*a(n-7) -11*a(n-8) -7*a(n-9) +2*a(n-10) +12*a(n-11) +18*a(n-12) +16*a(n-13) +3*a(n-14) -11*a(n-15) -20*a(n-16) -20*a(n-17) -11*a(n-18) +3*a(n-19) +16*a(n-20) +18*a(n-21) +12*a(n-22) +2*a(n-23) -7*a(n-24) -11*a(n-25) -8*a(n-26) -2*a(n-27) +2*a(n-28) +4*a(n-29) +3*a(n-30) +a(n-31) -a(n-32) -a(n-33).
%e Some solutions for n=3
%e ..3...-2...-1...-1....0....2....1....3...-3...-2...-1....2....0....2...-1....3
%e ..0...-2....1...-2...-1....2....3....1...-2....1...-2...-1....1...-1....2....2
%e ..0...-1....0...-1...-1....1....3....0...-3....2...-1...-2....3...-1....3....2
%e ..0...-1....2....1....0....2....0....1...-1....1....1....0....3....0....3....2
%e .-1....2....2....2....1....0...-3....1...-1...-2....2....1....3....1....3....2
%e ..0....2....0....2....0....0...-3....0...-2...-2....1...-1....0....0....1...-1
%e .-1....2...-2....0....0...-2...-2....1....0....0....3...-2...-1....2...-2...-1
%Y Cf. A201088.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 26 2011
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