A230895 Number of nX4 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4 and at least one element with value (x(i,j)-1) mod 4, no adjacent elements equal, and upper left element zero

0, 10, 34, 388, 2722, 23884, 190364, 1588552, 13012554, 107455420, 884594172, 7291800446, 60076189804, 495070806968, 4079377207736, 33615331820156, 276996500023710, 2282517482952278, 18808441293457304, 154985834999184838

Offset

1,2

Comments

Column 4 of A230899

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -62*a(n-2) -163*a(n-3) +1419*a(n-4) -597*a(n-5) -11402*a(n-6) +11509*a(n-7) +75373*a(n-8) -147277*a(n-9) -221783*a(n-10) +844791*a(n-11) -133903*a(n-12) -2328995*a(n-13) +2875761*a(n-14) +1867001*a(n-15) -7723572*a(n-16) +6157837*a(n-17) +4250299*a(n-18) -13856555*a(n-19) +11158502*a(n-20) +4066028*a(n-21) -17487812*a(n-22) +14075079*a(n-23) +3335956*a(n-24) -15535829*a(n-25) +10341667*a(n-26) +3227748*a(n-27) -9121594*a(n-28) +4301747*a(n-29) +2167024*a(n-30) -3620400*a(n-31) +1567341*a(n-32) +177244*a(n-33) -599284*a(n-34) +509560*a(n-35) -360030*a(n-36) +168518*a(n-37) -7893*a(n-38) -40976*a(n-39) +18013*a(n-40) +964*a(n-41) -1823*a(n-42) +30*a(n-43) +84*a(n-44) for n>45

Example

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

Crossrefs

Sequence in context: A221810 A219591 A272365 * A254674 A260336 A010818

Adjacent sequences: A230892 A230893 A230894 * A230896 A230897 A230898

Keyword

nonn

Author

R. H. Hardin, Oct 31 2013

Status

approved