A222387 Sum of neighbor maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to the sum mod 3 of their horizontal and antidiagonal neighbors in a random 0..2 2Xn array.

4, 16, 48, 248, 1024, 3968, 15872, 65536, 262144, 1048576, 4177632, 16777216, 67108864, 268435456, 1073479680, 4294961152, 17179869184, 68719378432, 274872664064, 1099511627776, 4398046511104, 17592186044416, 70368641459200

Offset: 1

Author

R. H. Hardin Feb 18 2013

Keywords

• nonn

Comments

Row 2 of A222386

Examples

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

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +32*a(n-4) -128*a(n-5) -256*a(n-8) +1024*a(n-9) +592*a(n-12) -2368*a(n-13) -18944*a(n-16) +75776*a(n-17) +151552*a(n-20) -606208*a(n-21) -109056*a(n-24) +436224*a(n-25) +3489792*a(n-28) -13959168*a(n-29) -27918336*a(n-32) [phone]*a(n-33) +6594560*a(n-36) -26378240*a(n-37) -211025920*a(n-40) [phone]*a(n-41) [phone]*a(n-44) -6752829440*a(n-45) -189071360*a(n-48) [phone]*a(n-49) [phone]*a(n-52) -24201134080*a(n-53) -48402268160*a(n-56) [phone]*a(n-57) [phone]*a(n-60) -11412701184*a(n-61) -91301609472*a(n-64) [phone]*a(n-65) [phone]*a(n-68) -2921651503104*a(n-69) -22011707392*a(n-72) [phone]*a(n-73) [phone]*a(n-76) -2817498546176*a(n-77) -5634997092352*a(n-80) [phone]*a(n-81) [phone]*a(n-84) -274877906944*a(n-85) -2199023255552*a(n-88) [phone]*a(n-89) [phone]*a(n-92) -70368744177664*a(n-93)