A237969 Number of (n+1)X(3+1) 0..3 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

7905, 59014, 369068, 2609908, 20123780, 149625960, 1103412332, 8201125448, 61392928964, 454158172752, 3384197190198, 25127260995252, 187313795410528, 1387556859816504, 10349189174713490, 76751150630045768, 572086176964557556

Offset

1,1

Comments

Column 3 of A237974

Links

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

Formula

Empirical: a(n) = 2894*a(n-4) +44487*a(n-6) -1503817*a(n-8) -30896235*a(n-10) +210299314*a(n-12) +4888817325*a(n-14) -14506815710*a(n-16) -273679187459*a(n-18) -437518653104*a(n-20) +9172444092579*a(n-22) +56036113474638*a(n-24) -195310008842740*a(n-26) -938665468143984*a(n-28) +2927054715784732*a(n-30) +2688466221818800*a(n-32) -21148892074250088*a(n-34) -56644046711903024*a(n-36) -9144467048901376*a(n-38) +77073773917450080*a(n-40) +63947939728517856*a(n-42) -43340863596329664*a(n-44) -24828004482833664*a(n-46) -1848578704883712*a(n-48) for n>53

Example

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

Crossrefs

Sequence in context: A045292 A115426 A206069 * A256163 A171111 A155178

Adjacent sequences: A237966 A237967 A237968 * A237970 A237971 A237972

Keyword

nonn

Author

R. H. Hardin, Feb 16 2014

Status

approved