A268807 Number of nX6 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.
336, 1972, 14308, 135912, 1316226, 12432856, 115671422, 1062318610, 9657289546, 87052567448, 779167091050, 6932066063186, 61353778718298, 540579543332426, 4744132651089162, 41488807479780664, 361699301828001722
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..1..0..1..0..0. .1..2..2..2..1..2. .2..1..2..2..2..2. .0..0..1..0..0..1 ..1..0..0..0..1..0. .1..2..2..2..2..1. .1..2..2..2..2..2. .0..0..1..0..0..0 ..0..0..1..0..0..0. .2..2..2..2..2..2. .2..1..2..2..2..1. .1..0..0..0..0..0 ..1..0..0..1..0..1. .2..2..2..2..2..1. .2..2..1..2..2..2. .0..1..0..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268809.
Formula
Empirical: a(n) = 2*a(n-1) +83*a(n-2) +210*a(n-3) -1918*a(n-4) -13444*a(n-5) -27431*a(n-6) +22868*a(n-7) +172414*a(n-8) +91292*a(n-9) -572846*a(n-10) -576908*a(n-11) +1569339*a(n-12) +1662464*a(n-13) -4129647*a(n-14) -2739590*a(n-15) +10005684*a(n-16) +128072*a(n-17) -18820309*a(n-18) +14239344*a(n-19) +18275195*a(n-20) -39512592*a(n-21) +16595129*a(n-22) +32600294*a(n-23) -63035320*a(n-24) +55225574*a(n-25) -27556538*a(n-26) +5959238*a(n-27) +1367780*a(n-28) -935764*a(n-29) -205936*a(n-30) +253428*a(n-31) -6946*a(n-32) -44268*a(n-33) +5192*a(n-34) +6896*a(n-35) -1085*a(n-36) -848*a(n-37) +74*a(n-38) +94*a(n-39) +3*a(n-40) -6*a(n-41) -a(n-42) for n>45
Comments