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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.
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 19 2015
STATUS
approved