A195965 Number of nX4 0..4 arrays with each element equal to the number its horizontal and vertical neighbors equal to itself

1, 1, 7, 21, 48, 118, 222, 527, 1370, 3336, 7717, 17897, 41296, 98631, 236602, 554717, 1304489, 3078621, 7242849, 17138388, 40496052, 95320672, 224944921, 530817100, 1251705990, 2954749967, 6970501275, 16438448824, 38788768683, 91508873268

Offset

1,3

Comments

Column 4 of A195969

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 6*a(n-3) +2*a(n-4) +19*a(n-5) +32*a(n-6) +22*a(n-7) +2*a(n-8) -31*a(n-9) +42*a(n-10) -133*a(n-11) -145*a(n-12) -88*a(n-13) -150*a(n-14) +149*a(n-15) -444*a(n-16) +236*a(n-17) +468*a(n-18) +54*a(n-19) +350*a(n-20) +126*a(n-21) +804*a(n-22) -1320*a(n-24) +640*a(n-25) +384*a(n-26) -704*a(n-27) for n>29

Example

Some solutions for n=5
..1..1..0..1....0..2..2..2....2..2..2..0....2..2..2..2....2..2..2..2
..2..2..2..1....2..2..0..2....2..0..2..2....2..1..1..2....2..0..1..2
..2..1..2..2....2..1..1..2....2..1..0..2....2..2..0..2....2..2..1..2
..2..1..0..2....2..2..2..2....2..1..2..2....1..2..2..2....1..2..0..2
..2..2..2..2....0..1..1..0....2..2..2..0....1..0..1..1....1..2..2..2

Crossrefs

Sequence in context: A146802 A147054 A146629 * A137182 A011927 A163723

Adjacent sequences: A195962 A195963 A195964 * A195966 A195967 A195968

Keyword

nonn

Author

R. H. Hardin Sep 25 2011

Status

approved