A301844 Number of 4Xn 0..1 arrays with every element equal to 0, 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.
8, 128, 773, 5748, 39703, 281758, 1986213, 14047365, 99396932, 703490647, 4979239708, 35242914039, 249447707376, 1765580587312, 12496708381182, 88451201375638, 626054067443912, 4431185705002395, 31363755611152388
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..1..1..0..1. .0..1..0..1..0. .0..1..1..0..0. .0..1..0..0..1 ..0..1..0..1..0. .0..1..0..1..1. .0..1..1..1..0. .1..0..1..0..0 ..1..0..1..1..0. .0..1..0..1..0. .0..0..1..0..1. .0..1..0..1..1 ..0..0..1..1..0. .0..1..1..0..1. .0..1..0..1..0. .1..1..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A301841.
Formula
Empirical: a(n) = 9*a(n-1) -11*a(n-2) -20*a(n-3) +4*a(n-4) +32*a(n-5) +164*a(n-6) -188*a(n-7) -490*a(n-8) +464*a(n-9) +542*a(n-10) -986*a(n-11) +3968*a(n-12) -8*a(n-13) -16968*a(n-14) +4086*a(n-15) +30368*a(n-16) -12378*a(n-17) -23854*a(n-18) +14224*a(n-19) +14464*a(n-20) -9340*a(n-21) -18074*a(n-22) +8682*a(n-23) +3861*a(n-24) +4655*a(n-25) -3137*a(n-26) +194*a(n-27) -1156*a(n-28) +662*a(n-29) -174*a(n-30) +60*a(n-31) -70*a(n-32) +8*a(n-33) +4*a(n-34) +4*a(n-35) for n>38
Comments