A303527 Number of 4Xn 0..1 arrays with every element equal to 0, 1, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

8, 10, 39, 103, 359, 1875, 8676, 36072, 166784, 848681, 4105851, 19152575, 92409752, 457395652, 2221962919, 10661835678, 51739845297, 253006224877, 1229143772638, 5947176017011, 28886071524170, 140636912306075, 683180817411487

Offset: 1

Author

R. H. Hardin, Apr 25 2018

Keywords

• nonn

Comments

Row 4 of A303525.

Examples

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

Links

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

Crossrefs

Cf. A303525.

Formula

Empirical: a(n) = 3*a(n-1) +9*a(n-2) -3*a(n-3) +227*a(n-4) -651*a(n-5) -2397*a(n-6) +2477*a(n-7) -10125*a(n-8) +32889*a(n-9) +140430*a(n-10) -139247*a(n-11) +147713*a(n-12) -696247*a(n-13) -3322631*a(n-14) +2870371*a(n-15) -589928*a(n-16) +7378532*a(n-17) [phone]*a(n-18) -28171654*a(n-19) -4215822*a(n-20) -41705374*a(n-21) -201340805*a(n-22) [phone]*a(n-23) [phone]*a(n-24) [phone]*a(n-25) [phone]*a(n-26) -296182026*a(n-27) -143995072*a(n-28) -140279497*a(n-29) -728134284*a(n-30) [phone]*a(n-31) [phone]*a(n-32) [phone]*a(n-33) [phone]*a(n-34) -287100410*a(n-35) -94828128*a(n-36) [phone]*a(n-37) -403974010*a(n-38) -39173927*a(n-39) [phone]*a(n-40) [phone]*a(n-41) [phone]*a(n-42) -42016893*a(n-43) [phone]*a(n-44) -9357240*a(n-45) -14553359*a(n-46) [phone]*a(n-47) -2991486*a(n-48) -1107750*a(n-49) +1176217*a(n-50) -526881*a(n-51) +173233*a(n-52) -21811*a(n-53) -19352*a(n-54) +9547*a(n-55) -1989*a(n-56) +87*a(n-57) +18*a(n-58) for n>60