OFFSET
1,1
COMMENTS
Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's
Column 4 of A197280
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) -4*a(n-2) +13*a(n-3) +24*a(n-4) +130*a(n-5) -534*a(n-6) -1467*a(n-7) -4061*a(n-8) -350*a(n-9) +660*a(n-10) +17309*a(n-11) +66603*a(n-12) +88830*a(n-13) +151269*a(n-14) +969572*a(n-15) +2151806*a(n-16) +3042232*a(n-17) +1395300*a(n-18) -2383750*a(n-19) -8156803*a(n-20) -13461098*a(n-21) -10627875*a(n-22) -2467733*a(n-23) +13987981*a(n-24) +20501622*a(n-25) +28114422*a(n-26) +30220361*a(n-27) +26876503*a(n-28) +11999640*a(n-29) -818003*a(n-30) +2977612*a(n-31) -6343090*a(n-32) -13797361*a(n-33) -12922199*a(n-34) -10283694*a(n-35) -4953615*a(n-36) -6395186*a(n-37) -4561904*a(n-38) -233451*a(n-39) -791355*a(n-40) -868034*a(n-41) -308312*a(n-42) -248750*a(n-43) +8267*a(n-44) +48879*a(n-45) -5430*a(n-46) -9498*a(n-47) -9755*a(n-48) -3296*a(n-49) -698*a(n-50) +3*a(n-51) +40*a(n-52) +2*a(n-53)
EXAMPLE
Some solutions containing all values 0 to 4 for n=5
..1..3..1..0....1..0..1..1....2..1..0..1....1..1..0..1....2..1..0..0
..0..1..3..0....3..1..3..0....1..4..1..1....0..1..1..1....1..4..1..1
..1..4..1..0....1..4..1..0....0..1..3..0....1..4..1..0....0..1..4..1
..1..1..4..1....0..1..1..0....0..1..1..0....3..1..4..1....0..3..1..0
..0..0..1..2....1..2..2..1....1..3..1..0....1..0..1..2....0..1..3..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 12 2011
STATUS
approved