A224132 Number of n X 7 0..1 arrays with rows nondecreasing and antidiagonals unimodal.

8, 64, 392, 2032, 9577, 42832, 186348, 799954, 3414588, 14548514, 61977436, 264133792, 1126197832, 4803498552, 20492542548, 87435004952, 373077010784, 1591916502840, 6792720587088, 28984532218344, 123676557316928

Offset

1,1

Comments

Column 7 of A224133.

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) + 18*a(n-3) - 4*a(n-4) + 2*a(n-5) + 8*a(n-6) + 32*a(n-7).

Empirical g.f.: x*(8 + 40*x^2 + 32*x^3 + 41*x^4 + 40*x^5 + 32*x^6) / (1 - 8*x + 20*x^2 - 18*x^3 + 4*x^4 - 2*x^5 - 8*x^6 - 32*x^7). - Colin Barker, Aug 27 2018

Example

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

Crossrefs

Cf. A224133.

Sequence in context: A228460 A202909 A203437 * A297376 A293888 A218267

Adjacent sequences: A224129 A224130 A224131 * A224133 A224134 A224135

Keyword

nonn

Author

R. H. Hardin, Mar 31 2013

Status

approved