A246899 Number of length 7+4 0..n arrays with some pair in every consecutive five terms totalling exactly n

1546, 140893, 2390116, 25710385, 139555230, 647845357, 2132283592, 6483573889, 16272395890, 38904095581, 82432596396, 168949326193, 318823302406, 587124413485, 1018357762960, 1733359959937, 2819557291482, 4517952689629

Offset

1,1

Comments

Row 7 of A246892

Links

R. H. Hardin, Table of n, a(n) for n = 1..59

Formula

Empirical: a(n) = 2*a(n-1) +7*a(n-2) -16*a(n-3) -20*a(n-4) +56*a(n-5) +28*a(n-6) -112*a(n-7) -14*a(n-8) +140*a(n-9) -14*a(n-10) -112*a(n-11) +28*a(n-12) +56*a(n-13) -20*a(n-14) -16*a(n-15) +7*a(n-16) +2*a(n-17) -a(n-18)

Example

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

Crossrefs

Sequence in context: A362507 A249008 A249473 * A090209 A283154 A157347

Adjacent sequences: A246896 A246897 A246898 * A246900 A246901 A246902

Keyword

nonn

Author

R. H. Hardin, Sep 06 2014

Status

approved