A268891 Number of 6Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.
0, 744, 12252, 236960, 3596174, 55491832, 800733668, 11458879568, 159796058742, 2205638713335, 30049236232518, 406011322471540, 5441799029248756, 72482603197808516, 960023683579703110, 12655255863840772464
Offset: 1
Keywords
Examples
Some solutions for n=3 ..1..0..0. .0..1..0. .1..0..1. .1..0..1. .1..0..1. .1..0..0. .0..0..1 ..0..1..0. .0..0..0. .0..1..0. .1..0..1. .1..0..0. .0..1..0. .1..0..0 ..0..0..1. .1..0..1. .0..0..0. .0..0..0. .0..0..1. .0..0..0. .0..1..1 ..0..0..1. .1..0..0. .0..0..1. .1..1..0. .1..0..1. .0..1..0. .0..0..1 ..1..0..1. .1..1..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0 ..0..1..0. .0..0..1. .0..0..0. .1..0..1. .1..1..0. .0..1..1. .0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268886.
Formula
Empirical: a(n) = 2*a(n-1) +237*a(n-2) +556*a(n-3) -17745*a(n-4) -102122*a(n-5) +202421*a(n-6) +2379616*a(n-7) -22987*a(n-8) -27364786*a(n-9) -13031593*a(n-10) +199889692*a(n-11) +91121845*a(n-12) -1012462462*a(n-13) -190133151*a(n-14) +3595273076*a(n-15) -642988498*a(n-16) -8640634728*a(n-17) +4929067410*a(n-18) +12985931924*a(n-19) -13174973746*a(n-20) -9991379232*a(n-21) +18252268246*a(n-22) +272964868*a(n-23) -13058804606*a(n-24) +5323457016*a(n-25) +4041105222*a(n-26) -3401387484*a(n-27) -210272991*a(n-28) +912442186*a(n-29) -169777035*a(n-30) -118543140*a(n-31) +43493135*a(n-32) +6734614*a(n-33) -4652195*a(n-34) -21632*a(n-35) +259061*a(n-36) -13682*a(n-37) -7961*a(n-38) +524*a(n-39) +133*a(n-40) -6*a(n-41) -a(n-42)
Comments