A236486 Number of (n+1)X(2+1) 0..2 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise

583, 9839, 155757, 2330087, 33951181, 486130993, 6894201989, 97206875033, 1366079758713, 19161171570845, 268469200940415, 3759218497139699, 52619787637621035, 736403139290490929, 10304687381116722953

Offset

1,1

Comments

Column 2 of A236490

Links

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

Formula

Empirical: a(n) = 25*a(n-1) -121*a(n-2) -1053*a(n-3) +8090*a(n-4) +14880*a(n-5) -181311*a(n-6) -23343*a(n-7) +2042880*a(n-8) -1467204*a(n-9) -12807271*a(n-10) +16480275*a(n-11) +45595086*a(n-12) -82190480*a(n-13) -90492369*a(n-14) +228270235*a(n-15) +90529737*a(n-16) -386567665*a(n-17) -14775664*a(n-18) +416825766*a(n-19) -67519824*a(n-20) -289624516*a(n-21) +80051920*a(n-22) +127462216*a(n-23) -43061200*a(n-24) -33607808*a(n-25) +12259456*a(n-26) +4677504*a(n-27) -1741568*a(n-28) -248832*a(n-29) +92160*a(n-30)

Example

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

Crossrefs

Sequence in context: A350663 A122694 A032373 * A236491 A235433 A205069

Adjacent sequences: A236483 A236484 A236485 * A236487 A236488 A236489

Keyword

nonn

Author

R. H. Hardin, Jan 27 2014

Status

approved