OFFSET
1,1
COMMENTS
Every 0 is next to 0 0's, every 1 is next to 1 1's, every 2 is next to 2 0's, every 3 is next to 3 0's, every 4 is next to 4 0's
Column 5 of A197475
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 15*a(n-2) +52*a(n-3) +296*a(n-4) -554*a(n-5) -229*a(n-6) -6613*a(n-7) -4335*a(n-8) -20874*a(n-9) +18040*a(n-10) +26381*a(n-11) +197933*a(n-12) +94070*a(n-13) +320192*a(n-14) -611325*a(n-15) -1087899*a(n-16) -3359414*a(n-17) -3589742*a(n-18) -3585120*a(n-19) +1625011*a(n-20) +12448300*a(n-21) +40979440*a(n-22) +72913510*a(n-23) +84642420*a(n-24) +58563471*a(n-25) -78408358*a(n-26) -285525148*a(n-27) -449083891*a(n-28) -430038062*a(n-29) -48315877*a(n-30) +332137526*a(n-31) +647232602*a(n-32) +895796784*a(n-33) +402347451*a(n-34) -71569578*a(n-35) -971116816*a(n-36) -915055737*a(n-37) -564795248*a(n-38) -408261834*a(n-39) +1616488905*a(n-40) +1209618295*a(n-41) +359637734*a(n-42) +1627078813*a(n-43) +458140995*a(n-44) -1790490027*a(n-45) -302830462*a(n-46) +118180618*a(n-47) -2049684292*a(n-48) -430429020*a(n-49) +1970991956*a(n-50) -371957378*a(n-51) -1143603688*a(n-52) +1515158904*a(n-53) +487108128*a(n-54) -935714152*a(n-55) +420116328*a(n-56) +641573360*a(n-57) -440594128*a(n-58) -327892352*a(n-59) +177462144*a(n-60) +7058112*a(n-61) -111894784*a(n-62) +26606336*a(n-63) +48291584*a(n-64) -3591168*a(n-65) -8124416*a(n-66) +135168*a(n-67) +61440*a(n-68) for n>71
EXAMPLE
Some solutions containing all values 0 to 4 for n=4
..0..2..0..2..1....0..2..1..1..0....2..0..1..1..0....1..1..2..0..2
..1..1..3..0..1....3..0..3..0..3....0..4..0..2..1....0..2..0..4..0
..0..3..0..4..0....0..4..0..3..0....3..0..1..0..1....2..1..3..0..3
..2..0..3..0..2....2..0..2..1..1....0..2..1..2..0....0..1..0..3..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 15 2011
STATUS
approved