A268796 Number of nX6 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.
240, 1714, 11948, 117062, 1158904, 11138352, 104971262, 974000420, 8927994302, 81031120788, 729449219322, 6521558348746, 57964319359808, 512593621373638, 4513059897036336, 39580897460175788, 345946165584055346
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..0..0..0..1. .2..1..1..2..2..2. .1..0..0..0..0..0. .0..1..0..1..0..0 ..0..0..0..1..0..1. .2..2..2..2..2..2. .0..0..0..0..0..0. .0..0..0..0..1..0 ..1..0..0..0..0..0. .2..2..2..2..2..2. .1..0..0..0..0..0. .0..0..1..0..0..0 ..0..0..1..0..0..1. .2..2..2..2..2..1. .0..0..1..1..0..1. .1..0..1..0..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268798.
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