A275354 Number of 4Xn 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,1) or (-1,-2) and new values introduced in order 0..2.

14, 216, 1024, 6156, 38256, 239112, 1530060, 9861340, 63978000, 416816872, 2721060036, 17793765428, 116463216432, 762750251516, 4997375137216, 32749260871852, 214647538572140, 1406987385055340, 9223158260357292

Offset: 1

Author

R. H. Hardin, Jul 24 2016

Keywords

• nonn

Comments

Row 4 of A275352.

Examples

			Some solutions for n=4
..0..1..0..1. .0..1..2..0. .0..1..2..1. .0..1..0..2. .0..1..2..2
..1..2..1..0. .1..2..1..0. .2..2..1..2. .1..2..2..0. .1..2..2..2
..2..1..0..1. .0..1..2..1. .2..1..0..1. .0..2..0..1. .0..1..0..0
..1..2..1..2. .0..0..1..2. .1..0..0..0. .1..0..1..1. .0..0..1..0
		

Links

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

Crossrefs

Cf. A275352.

Formula

Empirical: a(n) = 8*a(n-1) -7*a(n-2) -21*a(n-3) +109*a(n-4) -222*a(n-5) -1637*a(n-6) -1753*a(n-7) +4997*a(n-8) -35222*a(n-9) +99987*a(n-10) -192426*a(n-11) +427454*a(n-12) -488826*a(n-13) +530306*a(n-14) -497569*a(n-15) [phone]*a(n-16) +7508480*a(n-17) -6448250*a(n-18) -31426160*a(n-19) -127501000*a(n-20) -100384864*a(n-21) -411105760*a(n-22) [phone]*a(n-23) [phone]*a(n-24) [phone]*a(n-25) -2229093184*a(n-26) -48225424*a(n-27) -546260224*a(n-28) [phone]*a(n-29) -3333766656*a(n-30) [phone]*a(n-31) [phone]*a(n-32) [phone]*a(n-33) -7061796864*a(n-34) [phone]*a(n-35) -1038127104*a(n-36) [phone]*a(n-37) -4144545792*a(n-38) -3583180800*a(n-39) [phone]*a(n-40) -10319560704*a(n-41) for n>43