A220624 Number of ways to reciprocally link elements of an 5Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.
1, 228, 4657, 243119, 8608738, 356768525, 13864972277, 553125347136, 21831846871613, 865461975018339, 34247958158855874, 1356237159188241529, 53691862459540232153, 2125854494007156918632, 84166119627538600335289
Offset: 1
Keywords
Examples
Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10) ..9..0..0....0..7..0....6..4..0....0..7..0....0..6..4....0..0..7....0..6..4 ..0..1..0....3..7..0....0..0..0....3..7..0....0..9..0....0..3..0....0..7..0 ..6..4..7....3..6..4....0..6..4....3..6..4....0..0..1....0..9..0....3..7..0 ..9..3..0....0..7..7....0..6..4....6..4..0....6..4..0....6..4..1....3..0..0 ..0..1..0....3..3..0....0..6..4....6..4..0....0..0..0....0..6..4....6..4..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 29*a(n-1) +557*a(n-2) -4948*a(n-3) -24662*a(n-4) +187560*a(n-5) +182180*a(n-6) -1893504*a(n-7) -127344*a(n-8) +6325072*a(n-9) +132352*a(n-10) -7384448*a(n-11) -1323456*a(n-12) +2439808*a(n-13) +987648*a(n-14) -7168*a(n-15) -69632*a(n-16) +32768*a(n-17)
Comments