A304665 Number of nX4 0..1 arrays with every element unequal to 0, 1, 3, 5 or 6 king-move adjacent elements, with upper left element zero.

5, 21, 30, 93, 249, 544, 1366, 3399, 8219, 20292, 49933, 122347, 301036, 740028, 1817181, 4467409, 10981074, 26981337, 66317395, 163000592, 400583332, 984545201, 2419821691, 5947201372, 14616786659, 35924785775, 88293925192

Offset

1,1

Comments

Column 4 of A304669.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +14*a(n-3) -22*a(n-4) -3*a(n-5) -75*a(n-6) +93*a(n-7) +26*a(n-8) +215*a(n-9) -225*a(n-10) -93*a(n-11) -431*a(n-12) +399*a(n-13) +190*a(n-14) +679*a(n-15) -477*a(n-16) -271*a(n-17) -784*a(n-18) +455*a(n-19) +378*a(n-20) +790*a(n-21) -394*a(n-22) -421*a(n-23) -734*a(n-24) +146*a(n-25) +319*a(n-26) +472*a(n-27) -66*a(n-28) -251*a(n-29) -323*a(n-30) -245*a(n-31) -18*a(n-32) -128*a(n-33) +134*a(n-34) +128*a(n-35) +176*a(n-36) +40*a(n-37) -55*a(n-38) -63*a(n-39) -10*a(n-40) +6*a(n-41) +6*a(n-42) for n>43

Example

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

Crossrefs

Cf. A304669.

Sequence in context: A186304 A316235 A317156 * A306168 A305645 A316921

Adjacent sequences: A304662 A304663 A304664 * A304666 A304667 A304668

Keyword

nonn

Author

R. H. Hardin, May 16 2018

Status

approved