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

1,1

Comments

Column 2 of A265973.

Links

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

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) +17827872*a(n-18) +20705808*a(n-19) +4962208*a(n-20) -56431488*a(n-21) -79309568*a(n-22) -99599360*a(n-23) +85772288*a(n-24) +144689152*a(n-25) +353329152*a(n-26) -42172416*a(n-27) -139067392*a(n-28) -541589504*a(n-29) +2097152*a(n-30) +25165824*a(n-31) +301989888*a(n-32) for n>33

Example

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

Crossrefs

Cf. A265973.

Sequence in context: A231790 A125413 A160084 * A225873 A351925 A029987

Adjacent sequences: A265964 A265965 A265966 * A265968 A265969 A265970

Keyword

nonn

Author

R. H. Hardin, Dec 19 2015

Status

approved