A269034 Number of nX7 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

576, 6912, 198816, 4998648, 119790816, 2783857776, 63310818360, 1416701634552, 31304407671636, 684763778434512, 14854833017622684, 320017408314705960, 6853471478780510820, 146027732878366085832, 3097663460112852295020

Offset: 1

Author

R. H. Hardin, Feb 18 2016

Keywords

• nonn

Comments

Column 7 of A269035.

Examples

			Some solutions for n=3
..0..0..0..1..2..1..0. .1..2..2..1..2..1..0. .0..1..2..1..2..2..2
..0..0..0..1..0..1..2. .2..1..2..1..2..1..0. .0..1..2..1..2..1..2
..1..1..0..1..0..1..2. .0..1..2..1..0..1..2. .0..1..0..2..2..1..2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A269035.

Formula

Empirical: a(n) = 82*a(n-1) -2779*a(n-2) +50254*a(n-3) -514677*a(n-4) +2743554*a(n-5) -2950648*a(n-6) -48609034*a(n-7) [phone]*a(n-8) -89432156*a(n-9) -2444502643*a(n-10) [phone]*a(n-11) [phone]*a(n-12) -41716035658*a(n-13) [phone]*a(n-14) [phone]*a(n-15) -178302990168*a(n-16) -171928095488*a(n-17) [phone]*a(n-18) -70904009836*a(n-19) -621985038704*a(n-20) [phone]*a(n-21) [phone]*a(n-22) -522707244404*a(n-23) [phone]*a(n-24) [phone]*a(n-25) -140300285301*a(n-26) [phone]*a(n-27) [phone]*a(n-28) -9478840252*a(n-29) -368991021*a(n-30) [phone]*a(n-31) -172681320*a(n-32) -20355920*a(n-33) +9906636*a(n-34) -719568*a(n-35) -120720*a(n-36) +22272*a(n-37) -1024*a(n-38) for n>39