A265967 Number of nX2 0..4 arrays with the absolute differences of each element with its with horizontal and vertical neighbors unique.

25, 288, 1504, 7656, 38096, 190308, 953072, 4776628, 23912032, 119676172, 599079504, 2999395220, 15015056688, 75162919892, 376276088880, 1883701849404, 9429821433376, 47206168911396, 236319556068624, 1183033090841396

Offset: 1

Author

R. H. Hardin, Dec 19 2015

Keywords

• nonn

Comments

Column 2 of A265973.

Examples

			Some solutions for n=4
..3..0....3..0....4..4....2..2....2..3....0..1....3..1....2..3....2..3....4..1
..3..1....1..1....0..0....1..3....2..3....3..3....0..4....0..0....4..0....0..3
..0..1....0..3....3..3....1..0....0..0....4..4....0..3....1..4....3..1....0..4
..0..3....4..4....2..2....4..4....4..4....2..1....4..1....3..2....0..4....3..1
		

Links

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

Crossrefs

Cf. A265973.

Formula

Empirical: a(n) = 8*a(n-2) +76*a(n-3) +219*a(n-4) -150*a(n-5) -2179*a(n-6) -6990*a(n-7) -7878*a(n-8) +14114*a(n-9) +97811*a(n-10) +209622*a(n-11) +139056*a(n-12) -409764*a(n-13) -1836900*a(n-14) -2835340*a(n-15) -1654712*a(n-16) +6180672*a(n-17) [phone]*a(n-18) [phone]*a(n-19) +4962208*a(n-20) -56431488*a(n-21) -79309568*a(n-22) -99599360*a(n-23) [phone]*a(n-24) [phone]*a(n-25) [phone]*a(n-26) -42172416*a(n-27) -139067392*a(n-28) -541589504*a(n-29) +2097152*a(n-30) [phone]*a(n-31) [phone]*a(n-32) for n>33