A304897 Number of nX4 0..1 arrays with every element unequal to 1, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.

2, 86, 330, 2373, 13954, 88308, 546357, 3395402, 21113828, 131172423, 815495131, 5068082120, 31501875273, 195796100483, 1216969262017, 7564039441124, 47014056913283, 292214759342258, 1816252628655892, 11288871528329054

Offset

1,1

Comments

Column 4 of A304901.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 3*a(n-1) +25*a(n-2) -7*a(n-3) -142*a(n-4) -33*a(n-5) -65*a(n-6) -537*a(n-7) +1064*a(n-8) +2838*a(n-9) +970*a(n-10) -3560*a(n-11) -6459*a(n-12) +6033*a(n-13) -5863*a(n-14) +6939*a(n-15) +35098*a(n-16) -54497*a(n-17) +12078*a(n-18) -43634*a(n-19) +34947*a(n-20) +22730*a(n-21) -82308*a(n-22) +155432*a(n-23) -122335*a(n-24) +188320*a(n-25) -273271*a(n-26) +181445*a(n-27) -199138*a(n-28) +238069*a(n-29) -124583*a(n-30) +124586*a(n-31) -78418*a(n-32) +38490*a(n-33) -17797*a(n-34) -7870*a(n-35) +7590*a(n-36) -6928*a(n-37) +7875*a(n-38) -6027*a(n-39) +3984*a(n-40) -2232*a(n-41) +750*a(n-42) -348*a(n-43) +108*a(n-44) -16*a(n-45) +16*a(n-46) for n>48

Example

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

Crossrefs

Cf. A304901.

Sequence in context: A226842 A303892 A305284 * A316579 A304593 A316379

Adjacent sequences: A304894 A304895 A304896 * A304898 A304899 A304900

Keyword

nonn

Author

R. H. Hardin, May 20 2018

Status

approved