A240429 Number of nX3 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4

4, 24, 206, 970, 8084, 38406, 319164, 1514122, 12567490, 59600672, 494581142, 2345296116, 19460591828, 92279623108, 765699669972, 3630829114774, 30127086393190, 142857791342016, 1185372828609734, 5620845437561500

Offset

1,1

Comments

Column 3 of A240433

Links

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

Formula

Empirical: a(n) = 63*a(n-2) -1109*a(n-4) +7143*a(n-6) -395*a(n-8) -201246*a(n-10) +762860*a(n-12) +347011*a(n-14) -7366154*a(n-16) +11744674*a(n-18) +3758987*a(n-20) +10095295*a(n-22) -126415852*a(n-24) +204390541*a(n-26) -65238786*a(n-28) -59211883*a(n-30) -114625640*a(n-32) +381020006*a(n-34) -342073760*a(n-36) +16725276*a(n-38) +181283664*a(n-40) -110895680*a(n-42) +16492080*a(n-44) +1175136*a(n-46) +390464*a(n-48)

Example

Some solutions for n=4
..1..3..1....3..1..3....3..1..3....3..1..1....1..3..1....1..3..3....3..1..3
..3..1..2....1..0..2....1..0..2....1..2..2....3..0..2....3..2..2....1..2..1
..3..2..2....1..2..0....1..0..3....1..0..2....3..2..0....3..2..0....3..0..2
..1..0..2....3..2..3....3..0..2....3..0..0....1..2..1....1..0..2....1..0..0

Crossrefs

Sequence in context: A012244 A378094 A342168 * A240297 A050388 A241980

Adjacent sequences: A240426 A240427 A240428 * A240430 A240431 A240432

Keyword

nonn

Author

R. H. Hardin, Apr 04 2014

Status

approved