A242545 Number of length n+3 0..4 arrays with no four elements in a row with pattern aabb (possibly a=b) and new values 0..4 introduced in 0..4 order

13, 43, 165, 690, 3050, 13988, 65588, 311431, 1489435, 7152787, 34431086, 165959996, 800539194, 3863197403, 18647303797, 90021133115, 434616726192, 2098395654912, 10131623972784, 48918915963483, 236198983546635

Offset

1,1

Comments

Column 4 of A242549

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -14*a(n-2) +29*a(n-3) -53*a(n-4) -18*a(n-5) -28*a(n-6) -56*a(n-7) +140*a(n-8) +176*a(n-9) +192*a(n-10) +192*a(n-11) +64*a(n-12).

Empirical: G.f.: -x*(13 -48*x +46*x^2 -240*x^3 -28*x^4 +26*x^5 +245*x^6 +1169*x^7 +1276*x^8 +1240*x^9 +992*x^10 +296*x^11) / ( (2*x^2+2*x-1) *(x^2+x-1) *(2*x^2+1) *(x^2+1) *(4*x^2+1) *(4*x^2+4*x-1) ). - R. J. Mathar, May 18 2014

Example

Some solutions for n=4
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....0....1....1....1....1....1....0....0....1....1....1....1....1
..2....2....0....1....2....1....1....2....0....1....0....2....2....2....2....2
..1....3....2....2....3....2....2....3....2....2....1....3....3....1....1....3
..3....2....1....0....3....3....3....2....0....3....2....3....0....2....1....3
..1....3....2....3....1....2....0....1....2....2....3....0....1....0....2....3
..0....3....1....3....2....4....0....3....0....2....3....1....4....0....3....1

Crossrefs

Sequence in context: A243031 A243032 A269236 * A242546 A242547 A242548

Adjacent sequences: A242542 A242543 A242544 * A242546 A242547 A242548

Keyword

nonn

Author

R. H. Hardin, May 17 2014

Status

approved