OFFSET
1,3
COMMENTS
Every 0 is next to 0 0's, every 1 is next to 1 3'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 A197623
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-2) +35*a(n-3) +73*a(n-4) +132*a(n-5) -151*a(n-6) -1628*a(n-7) -3858*a(n-8) -3164*a(n-9) +14500*a(n-10) +38136*a(n-11) +38354*a(n-12) -54500*a(n-13) -185382*a(n-14) -106998*a(n-15) -128239*a(n-16) -546331*a(n-17) -1772634*a(n-18) -441963*a(n-19) +6472386*a(n-20) +12393365*a(n-21) +1267839*a(n-22) -10077007*a(n-23) -1840713*a(n-24) +20945699*a(n-25) +25184992*a(n-26) -19820871*a(n-27) -46956209*a(n-28) +19893087*a(n-29) +53217731*a(n-30) +2842210*a(n-31) -10754502*a(n-32) -5041230*a(n-33) +13053780*a(n-34) -2938224*a(n-35) -1474052*a(n-36) +654048*a(n-37) -165728*a(n-38) +136032*a(n-39) -31456*a(n-40) -2112*a(n-41) for n>42
EXAMPLE
Some solutions containing all values 0 to 4 for n=5
..2..1..3..1....1..3..1..0....2..1..3..1....1..1..3..1....0..1..3..1
..1..0..1..1....2..1..4..1....1..4..1..1....3..1..1..1....1..4..1..2
..3..1..1..3....0..2..1..3....3..1..1..3....1..0..1..3....3..1..2..0
..1..1..4..1....1..3..1..1....1..1..0..1....0..1..4..1....1..1..3..1
..1..3..1..2....0..1..2..0....1..3..1..2....1..3..1..2....0..2..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 16 2011
STATUS
approved