A302071 Number of 4Xn 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

8, 128, 884, 7070, 54177, 420121, 3247765, 25151723, 194858064, 1509933667, 11700696791, 90670424899, 702618377845, 5444692727615, 42191725016453, 326949892917866, 2533582903716510, 19633107331640883, 152139842374919901

Offset

1,1

Comments

Row 4 of A302069.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -7*a(n-2) -29*a(n-3) +72*a(n-4) -52*a(n-5) -176*a(n-6) +353*a(n-7) -344*a(n-8) -507*a(n-9) +1488*a(n-10) -860*a(n-11) -872*a(n-12) +6458*a(n-13) +967*a(n-14) -10158*a(n-15) +2015*a(n-16) +9555*a(n-17) -22359*a(n-18) -15321*a(n-19) +31037*a(n-20) +1946*a(n-21) -35762*a(n-22) +6984*a(n-23) +54512*a(n-24) -8022*a(n-25) -4993*a(n-26) +14111*a(n-27) +19649*a(n-28) -10813*a(n-29) -13238*a(n-30) +10142*a(n-31) -41279*a(n-32) +14522*a(n-33) -20026*a(n-34) -4521*a(n-35) -2506*a(n-36) +13706*a(n-37) -2834*a(n-38) +7163*a(n-39) +1796*a(n-40) +817*a(n-41) -1442*a(n-42) +116*a(n-43) -719*a(n-44) -133*a(n-45) +120*a(n-46) -123*a(n-47) -23*a(n-48) -a(n-49) -7*a(n-50) -20*a(n-51) +10*a(n-52) +8*a(n-53) for n>58

Example

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

Crossrefs

Cf. A302069.

Sequence in context: A301844 A302268 A302967 * A301822 A302810 A061549

Adjacent sequences: A302068 A302069 A302070 * A302072 A302073 A302074

Keyword

nonn

Author

R. H. Hardin, Mar 31 2018

Status

approved