A223948 Number of n X 7 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.

8, 64, 352, 1479, 5233, 16845, 52532, 166076, 545443, 1866509, 6584260, 23605163, 85081408, 306598781, 1103114341, 3965858837, 14265857551, 51394273661, 185496356237, 670659535731, 2428046038680, 8798879746069, 31906100994095

Offset

1,1

Comments

Column 7 of A223949.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -20*a(n-2) +11*a(n-3) +23*a(n-4) -32*a(n-5) +18*a(n-6) -37*a(n-7) +65*a(n-8) -257*a(n-9) -274*a(n-10) -1437*a(n-11) +3612*a(n-12) +1576*a(n-13) +6921*a(n-14) +449*a(n-15) +4935*a(n-16) +22314*a(n-17) +7279*a(n-18) -8809*a(n-19) -58688*a(n-20) -81734*a(n-21) -86761*a(n-22) -2940*a(n-23) -21650*a(n-24) +16326*a(n-25) +13737*a(n-26) +26159*a(n-27) +10634*a(n-28) +2502*a(n-29) -384*a(n-30) -24*a(n-31) -80*a(n-32) -16*a(n-33).

Example

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

Crossrefs

Cf. A223949.

Sequence in context: A356703 A267189 A181480 * A224151 A225014 A228460

Adjacent sequences: A223945 A223946 A223947 * A223949 A223950 A223951

Keyword

nonn

Author

R. H. Hardin, Mar 29 2013

Status

approved