cp's OEIS Frontend

A202968 Number of arrays of 8 integers in -n..n with sum zero and adjacent elements differing in absolute value.

%I A202968 #7 Jul 22 2025 16:54:24
%S A202968 12,1724,47732,447528,2475008,9824176,31155004,84017312,200493156,
%T A202968 434793200,873257136,1646890444,2946873064,5043331924,8307662160,
%U A202968 13238602092,20492707704,30919086656,45598979576,65890555856,93479027928
%N A202968 Number of arrays of 8 integers in -n..n with sum zero and adjacent elements differing in absolute value.
%C A202968 Row 6 of A202962
%H A202968 R. H. Hardin, <a href="/A202968/b202968.txt">Table of n, a(n) for n = 1..210</a>
%F A202968 Empirical: a(n) = a(n-2) +3*a(n-3) +a(n-4) -a(n-5) -4*a(n-6) -4*a(n-7) -3*a(n-8) +a(n-9) +5*a(n-10) +6*a(n-11) +5*a(n-12) -2*a(n-14) -5*a(n-15) -4*a(n-16) -5*a(n-17) -2*a(n-18) +5*a(n-20) +6*a(n-21) +5*a(n-22) +a(n-23) -3*a(n-24) -4*a(n-25) -4*a(n-26) -a(n-27) +a(n-28) +3*a(n-29) +a(n-30) -a(n-32)
%e A202968 Some solutions for n=3
%e A202968 ..2....1....3....2....2....3....2....2....0....0....1...-1....0....1....1...-1
%e A202968 .-3....3....0....1...-3....0....1....3....2....2....0....0...-2....0....0....0
%e A202968 .-1...-2...-1....3....2...-1...-3....1...-3...-1....2....3....3....2....3....2
%e A202968 ..0...-3....0...-2...-1...-2....0...-2....1....2....0....2....0...-3...-2....1
%e A202968 ..2....1...-3....1....2....3....2...-1....3....0...-2...-3...-3....0....0...-3
%e A202968 .-1...-2....0...-3...-3....0....0....0...-2...-2...-3....0....1...-3...-3....0
%e A202968 .-2....3....3....0....1...-1...-3...-2....0...-3...-1...-3....0....0...-2...-1
%e A202968 ..3...-1...-2...-2....0...-2....1...-1...-1....2....3....2....1....3....3....2
%K A202968 nonn
%O A202968 1,1
%A A202968 _R. H. Hardin_ Dec 26 2011