A300368 Number of nX4 0..1 arrays with every element equal to 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 1, 3, 3, 4, 22, 39, 102, 298, 833, 2105, 6065, 16665, 45374, 126224, 348868, 962054, 2662783, 7364465, 20366371, 56334291, 155844294, 431150954, 1192657061, 3299782775, 9128883051, 25255840216, 69873935349, 193313945656, 534830511278

Offset

1,3

Comments

Column 4 of A300372.

Links

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

Formula

Empirical: a(n) = 4*a(n-2) +8*a(n-3) +8*a(n-4) +12*a(n-5) -44*a(n-7) -152*a(n-8) -241*a(n-9) -140*a(n-10) -68*a(n-11) -156*a(n-12) +283*a(n-13) +514*a(n-14) +1368*a(n-15) +980*a(n-16) +28*a(n-17) -659*a(n-18) -792*a(n-19) -790*a(n-20) -705*a(n-21) -657*a(n-22) +8*a(n-23) +390*a(n-24) +453*a(n-25) -341*a(n-26) +569*a(n-27) -377*a(n-28) +201*a(n-29) -183*a(n-30) -139*a(n-31) +314*a(n-32) -196*a(n-33) +10*a(n-34) +78*a(n-35) -34*a(n-36) +2*a(n-37) -24*a(n-38) +52*a(n-39) -52*a(n-40) +28*a(n-41) -8*a(n-42) +a(n-43) for n>45

Example

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

Crossrefs

Cf. A300372.

Sequence in context: A118114 A366555 A266067 * A306521 A300369 A304296

Adjacent sequences: A300365 A300366 A300367 * A300369 A300370 A300371

Keyword

nonn

Author

R. H. Hardin, Mar 04 2018

Status

approved