cp's OEIS Frontend

A189439 Number of 7Xn array permutations with each element not moving, or moving one space N, SW or SE.

%I A189439 #7 Jul 22 2025 11:45:08
%S A189439 1,85,1245,26589,493941,9557077,181540773,3467525301,66045131269,
%T A189439 1258981901653,23988387057381,457127606313333,8710469146675973,
%U A189439 165979359956189589,3162723963901817637,60265641669988070325
%N A189439 Number of 7Xn array permutations with each element not moving, or moving one space N, SW or SE.
%C A189439 Row 7 of A189435
%H A189439 R. H. Hardin, <a href="/A189439/b189439.txt">Table of n, a(n) for n = 1..200</a>
%F A189439 Empirical: a(n) = 23*a(n-1) +26*a(n-2) -2256*a(n-3) +3272*a(n-4) +63936*a(n-5) -101752*a(n-6) -714624*a(n-7) +1041216*a(n-8) +3522752*a(n-9) -4444032*a(n-10) -7691264*a(n-11) +5545472*a(n-12) +11157504*a(n-13) -4947968*a(n-14) -4030464*a(n-15)
%e A189439 Some solutions for 7X3
%e A189439 ..0..1..2....3..1..2....3..1..2....0..1..2....0..1..2....3..4..2....0..1..2
%e A189439 ..3..7..8....6..0..5....6..0..5....3..4..5....3..4..5....1..0..5....6..7..5
%e A189439 ..6..5..4....9..7..4....4.10.11....6..7..8....6..7.11....6.10.11....4..3..8
%e A189439 ..9.13.14...12..8.14....9..8..7...12.13.11...12..8.14....7..8.14....9.13.14
%e A189439 .12.11.10...15.11.10...12.13.17...10..9.14...15..9.10...12..9.17...12.11.10
%e A189439 .15.19.20...13.19.20...15.14.20...15.19.20...18.19.13...18.19.13...18.19.17
%e A189439 .18.17.16...18.17.16...18.19.16...18.17.16...16.17.20...16.15.20...16.15.20
%K A189439 nonn
%O A189439 1,2
%A A189439 _R. H. Hardin_ Apr 22 2011