A239181 Number of (3+1)X(n+1) 0..2 arrays with no element greater than all horizontal neighbors or equal to all vertical neighbors

36, 676, 9604, 142884, 2286144, 36216324, 570732100, 8995763716, 141880288900, 2237680908544, 35289896680900, 556546510372644, 8777179394306404, 138423129725708100, 2183042242048352400, 34428300464251842724

Offset

1,1

Comments

Row 3 of A239178

Links

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

Formula

Empirical: a(n) = 15*a(n-1) +148*a(n-3) +922*a(n-4) -3635*a(n-5) -1087*a(n-6) +8846*a(n-7) -4276*a(n-8) +5182*a(n-9) +542*a(n-10) -22842*a(n-11) +14936*a(n-12) -4238*a(n-13) +2914*a(n-14) +1585*a(n-15) -189*a(n-16) +354*a(n-17) -18*a(n-18) -50*a(n-19) +13*a(n-20) -a(n-21)

Example

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

Crossrefs

Sequence in context: A000815 A271794 A182678 * A053947 A157092 A004419

Adjacent sequences: A239178 A239179 A239180 * A239182 A239183 A239184

Keyword

nonn

Author

R. H. Hardin, Mar 11 2014

Status

approved