A302227 Number of 4Xn 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

0, 34, 194, 934, 6110, 38736, 251254, 1610569, 10296766, 66243864, 424625879, 2726394062, 17497812841, 112298621494, 720825717366, 4626342158809, 29694255667486, 190589162278017, 1223278644711981, 7851527608519228

Offset

1,2

Comments

Row 4 of A302224.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +46*a(n-2) -788*a(n-4) -646*a(n-5) +6434*a(n-6) +6201*a(n-7) -28548*a(n-8) -19144*a(n-9) +59264*a(n-10) -8209*a(n-11) +97963*a(n-12) +207006*a(n-13) -1098204*a(n-14) -507314*a(n-15) +3485081*a(n-16) +276950*a(n-17) -5506599*a(n-18) +473443*a(n-19) +2482943*a(n-20) +506556*a(n-21) +8109563*a(n-22) -4109434*a(n-23) -21303483*a(n-24) +5376215*a(n-25) +28671693*a(n-26) -135719*a(n-27) -26171138*a(n-28) -6896727*a(n-29) +15548107*a(n-30) +8991124*a(n-31) -3953690*a(n-32) -5343561*a(n-33) -1641633*a(n-34) +576769*a(n-35) +1453672*a(n-36) +1139326*a(n-37) -138815*a(n-38) -702483*a(n-39) -125657*a(n-40) +244637*a(n-41) +55357*a(n-42) -68301*a(n-43) -34287*a(n-44) +3547*a(n-45) +16186*a(n-46) +4392*a(n-47) -3502*a(n-48) -1602*a(n-49) +56*a(n-50) +268*a(n-51) +140*a(n-52) -16*a(n-53) -16*a(n-54) for n>58

Example

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

Crossrefs

Cf. A302224.

Sequence in context: A200256 A074709 A074900 * A058581 A050263 A020869

Adjacent sequences: A302224 A302225 A302226 * A302228 A302229 A302230

Keyword

nonn

Author

R. H. Hardin, Apr 03 2018

Status

approved