A301844 Number of 4Xn 0..1 arrays with every element equal to 0, 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.

8, 128, 773, 5748, 39703, 281758, 1986213, 14047365, 99396932, 703490647, 4979239708, 35242914039, 249447707376, 1765580587312, 12496708381182, 88451201375638, 626054067443912, 4431185705002395, 31363755611152388

Offset

1,1

Comments

Row 4 of A301841.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -11*a(n-2) -20*a(n-3) +4*a(n-4) +32*a(n-5) +164*a(n-6) -188*a(n-7) -490*a(n-8) +464*a(n-9) +542*a(n-10) -986*a(n-11) +3968*a(n-12) -8*a(n-13) -16968*a(n-14) +4086*a(n-15) +30368*a(n-16) -12378*a(n-17) -23854*a(n-18) +14224*a(n-19) +14464*a(n-20) -9340*a(n-21) -18074*a(n-22) +8682*a(n-23) +3861*a(n-24) +4655*a(n-25) -3137*a(n-26) +194*a(n-27) -1156*a(n-28) +662*a(n-29) -174*a(n-30) +60*a(n-31) -70*a(n-32) +8*a(n-33) +4*a(n-34) +4*a(n-35) for n>38

Example

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

Crossrefs

Cf. A301841.

Sequence in context: A093586 A238651 A291849 * A302268 A302967 A302071

Adjacent sequences: A301841 A301842 A301843 * A301845 A301846 A301847

Keyword

nonn

Author

R. H. Hardin, Mar 27 2018

Status

approved