A212465 Number of 0..3 arrays of length n+3 with sum no more than 6 in any length 4 subsequence (=50% duty cycle)

150, 486, 1597, 5211, 16649, 53553, 172980, 558743, 1801720, 5808944, 18737526, 60447764, 194984049, 628912080, 2028584905, 6543438398, 21106550023, 68080857417, 219600230083, 708339701336, 2284812500323, 7369860423165

Offset

1,1

Comments

Column 2 of A212471

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-2) +17*a(n-4) -8*a(n-5) -42*a(n-6) -8*a(n-7) -59*a(n-8) +26*a(n-9) +147*a(n-10) +33*a(n-11) +112*a(n-12) -115*a(n-13) -293*a(n-14) -5*a(n-15) -93*a(n-16) +221*a(n-17) +370*a(n-18) -65*a(n-19) +3*a(n-20) -242*a(n-21) -279*a(n-22) +78*a(n-23) +21*a(n-24) +176*a(n-25) +184*a(n-26) -33*a(n-27) -15*a(n-28) -87*a(n-29) -132*a(n-30) -7*a(n-31) +36*a(n-32) +35*a(n-33) +69*a(n-34) +5*a(n-35) -30*a(n-36) -10*a(n-37) -20*a(n-38) +10*a(n-40) +a(n-41) +2*a(n-42) -a(n-44)

Example

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

Crossrefs

Sequence in context: A291959 A210643 A211550 * A273322 A206066 A140671

Adjacent sequences: A212462 A212463 A212464 * A212466 A212467 A212468

Keyword

nonn

Author

R. H. Hardin May 17 2012

Status

approved