A200663 Number of 0..3 arrays x(0..n-1) of n elements with each no smaller than the sum of its three previous neighbors modulo 4

4, 10, 26, 69, 175, 432, 1076, 2671, 6627, 16421, 40695, 100886, 250093, 619947, 1536810, 3809790, 9444489, 23412999, 58041252, 143885484, 356695266, 884255363, 2192088651, 5434237397, 13471597487, 33396394603, 82790419927, 205239329905

Offset

1,1

Comments

Column 3 of A200668

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -a(n-3) -6*a(n-4) -2*a(n-5) +4*a(n-6) +10*a(n-7) +8*a(n-8) -4*a(n-9) -37*a(n-10) +12*a(n-11) +5*a(n-12) +27*a(n-13) +6*a(n-14) -10*a(n-15) -25*a(n-16) -a(n-17) +23*a(n-19) -7*a(n-20) -14*a(n-21) -9*a(n-22) +94*a(n-23) -90*a(n-24) -38*a(n-25) +88*a(n-26) -72*a(n-27) +64*a(n-28) +75*a(n-29) -94*a(n-30) -141*a(n-31) +114*a(n-32) +23*a(n-33) +71*a(n-34) -49*a(n-35) -58*a(n-36) -100*a(n-37) +48*a(n-38) +140*a(n-39) -56*a(n-40) +32*a(n-41) -43*a(n-42) +18*a(n-43) +6*a(n-44) -14*a(n-45) -10*a(n-46) -12*a(n-47) +27*a(n-48) -2*a(n-49) -4*a(n-50) +6*a(n-51) -6*a(n-52) -2*a(n-53) +3*a(n-54) +3*a(n-55) -2*a(n-56) -a(n-57) +5*a(n-58) -5*a(n-59) +2*a(n-63) -a(n-64)

Example

Some solutions for n=6
..0....2....0....1....1....2....3....1....1....1....2....2....0....1....0....2
..3....3....2....1....1....2....3....3....3....1....2....3....2....3....3....2
..3....3....2....3....2....0....3....0....0....2....3....3....2....1....3....0
..2....2....1....2....1....2....2....1....2....3....3....3....1....1....3....3
..3....0....1....3....3....3....3....1....2....3....0....2....1....1....2....1
..1....2....3....2....2....3....3....3....2....1....3....1....2....3....1....1

Crossrefs

Sequence in context: A207095 A126358 A200051 * A200464 A099234 A087222

Adjacent sequences: A200660 A200661 A200662 * A200664 A200665 A200666

Keyword

nonn

Author

R. H. Hardin Nov 20 2011

Status

approved