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
Keywords
Examples
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
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A300372.
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
Comments