A318342 Number of nX7 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
64, 190, 344, 817, 3321, 16267, 86487, 476348, 2647555, 14797928, 82863837, 464502820, 2605038853, 14613251568, 81984567828, 459986291171, 2580903334169, 14481247495703, 81253869292071, 455915278972371, 2558145839414926
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .0..1..1..1..1..1..1 ..0..0..1..0..0..0..0. .0..0..0..1..0..1..0. .1..1..1..1..1..1..0 ..0..0..0..0..0..0..1. .0..0..0..0..0..0..0. .1..0..1..1..1..0..0 ..0..0..0..0..0..1..1. .0..0..0..1..0..1..0. .1..1..1..1..0..0..1 ..0..0..0..0..1..1..1. .0..0..0..0..0..0..0. .1..1..1..0..0..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A318343.
Formula
Empirical: a(n) = 6*a(n-1) +15*a(n-2) -89*a(n-3) -165*a(n-4) +555*a(n-5) +1215*a(n-6) -1671*a(n-7) -5290*a(n-8) +1469*a(n-9) +13428*a(n-10) +5625*a(n-11) -17967*a(n-12) -19967*a(n-13) +3366*a(n-14) +22938*a(n-15) +28588*a(n-16) +12646*a(n-17) -41780*a(n-18) -75067*a(n-19) +9433*a(n-20) +89071*a(n-21) +52784*a(n-22) -43392*a(n-23) -74658*a(n-24) -40*a(n-25) +41248*a(n-26) +12244*a(n-27) -12324*a(n-28) -4868*a(n-29) +3028*a(n-30) +660*a(n-31) -1352*a(n-32) -152*a(n-33) +496*a(n-34) +32*a(n-35) -64*a(n-36) for n>41
Comments