A302208 Number of nX4 0..1 arrays with every element equal to 0, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1, 13, 5, 7, 18, 55, 172, 575, 1962, 6756, 23400, 81288, 283089, 987275, 3444621, 12023434, 41982749, 146612525, 512036344, 1788383898, 6246509941, 21818284060, 76209472929, 266195826556, 929812279542, 3247807389634, 11344517688838
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..1..1. .0..0..1..0. .0..1..0..0. .0..0..1..1. .0..0..1..1 ..0..0..1..1. .0..0..1..0. .0..1..0..0. .0..0..1..1. .0..0..1..1 ..1..0..1..1. .1..1..1..1. .1..1..1..1. .1..0..0..1. .1..1..0..0 ..0..0..1..1. .0..1..0..0. .0..0..1..0. .0..0..1..1. .1..1..0..0 ..0..0..1..1. .0..1..0..0. .0..0..1..0. .0..0..1..1. .1..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A302212.
Formula
Empirical: a(n) = 4*a(n-1) -3*a(n-2) +12*a(n-3) -21*a(n-4) -18*a(n-5) -16*a(n-6) +14*a(n-7) +21*a(n-8) +37*a(n-9) -6*a(n-10) +25*a(n-11) +62*a(n-12) -20*a(n-13) -7*a(n-14) -75*a(n-15) -76*a(n-16) -51*a(n-17) +57*a(n-18) +43*a(n-19) +35*a(n-20) +30*a(n-21) -35*a(n-22) -27*a(n-23) +10*a(n-24) +2*a(n-25) +6*a(n-26) -2*a(n-28) for n>32
Comments