A251446 Number of (n+1)X(3+1) 0..2 arrays with no 2X2 subblock having the minimum of its diagonal elements less than the absolute difference of its antidiagonal elements

1223, 26633, 618813, 14434472, 337561156, 7891330499, 184506926190, 4313788353029, 100857947002791, 2358088130470091, 55132839599212279, 1289022728657810183, 30137749824993417503, 704629890796131084465

Offset

1,1

Comments

Column 3 of A251451

Links

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

Formula

Empirical: a(n) = 17*a(n-1) +201*a(n-2) -876*a(n-3) -8635*a(n-4) +13006*a(n-5) +131844*a(n-6) -111182*a(n-7) -931289*a(n-8) +1032555*a(n-9) +3304892*a(n-10) -7872203*a(n-11) -8207830*a(n-12) +24043132*a(n-13) +11303035*a(n-14) -30232428*a(n-15) -17085802*a(n-16) +10132677*a(n-17) +57114512*a(n-18) -18262991*a(n-19) -78796352*a(n-20) +63528530*a(n-21) +15506828*a(n-22) -32421339*a(n-23) +3367598*a(n-24) +9344702*a(n-25) -3285299*a(n-26) -1421443*a(n-27) +750598*a(n-28) -121690*a(n-29) -42594*a(n-30) +227931*a(n-31) -13269*a(n-32) -41504*a(n-33) -156*a(n-34) +1469*a(n-35) -24*a(n-36) for n>37

Example

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

Crossrefs

Sequence in context: A328991 A223118 A128655 * A014488 A229379 A229371

Adjacent sequences: A251443 A251444 A251445 * A251447 A251448 A251449

Keyword

nonn

Author

R. H. Hardin, Dec 02 2014

Status

approved