A265961 Number of nX2 integer arrays with each element equal to the number of horizontal, vertical and antidiagonal neighbors less than or equal to itself.

3, 8, 50, 1491, 7741, 82424, 763505, 6210500, 59946891, 519317082, 4648314729, 41998409548, 372087286538, 3343130550271, 29871977852857, 266886700884439, 2389390603377066, 21353641948385927, 190995707152937241

Offset

1,1

Comments

Column 2 of A265965.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +21*a(n-2) +203*a(n-3) +238*a(n-4) +4932*a(n-5) -849*a(n-6) +1928*a(n-7) -121174*a(n-8) -213452*a(n-9) -1661362*a(n-10) -1851417*a(n-11) +1090499*a(n-12) +11973623*a(n-13) +3597843*a(n-14) +4813209*a(n-15) -34905904*a(n-16) +30566100*a(n-17) -51580886*a(n-18) +30604488*a(n-19) -34706660*a(n-20) +227606392*a(n-21) +121796739*a(n-22) -26131615*a(n-23) -219798407*a(n-24) -65796547*a(n-25) +157754498*a(n-26) +21801560*a(n-27) -33218767*a(n-28) +34577383*a(n-29) +11740953*a(n-30) -15006230*a(n-31) -5174032*a(n-32) +8271454*a(n-33) -2211321*a(n-34) +302698*a(n-35) +259499*a(n-36) +410728*a(n-37) -251580*a(n-38) +104016*a(n-39) -18192*a(n-40) +1024*a(n-41)

Example

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

Crossrefs

Cf. A265965.

Sequence in context: A222684 A208801 A019044 * A019035 A241469 A153385

Adjacent sequences: A265958 A265959 A265960 * A265962 A265963 A265964

Keyword

nonn

Author

R. H. Hardin, Dec 19 2015

Status

approved