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A223953 Number of 6 X n 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing. 1
64, 729, 2024, 3645, 5951, 9919, 16845, 28558, 47721, 78071, 124691, 194314, 295659, 439799, 640561, 914958, 1283653, 1771455, 2407847, 3227546, 4271095, 5585487, 7224821, 9250990, 11734401, 14754727, 18401691, 22775882, 27989603, 34167751 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 6 of A223949.

LINKS

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

FORMULA

Empirical: a(n) = (2/45)*n^6 + (67/36)*n^4 + 8*n^3 + (7757/180)*n^2 + 138*n + 1326 for n>4.

Conjectures from Colin Barker, Aug 24 2018: (Start)

G.f.: x*(64 + 281*x - 1735*x^2 + 2546*x^3 - 335*x^4 - 1862*x^5 + 787*x^6 + 767*x^7 - 426*x^8 - 148*x^9 + 93*x^10) / (1 - x)^7.

a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>11.

(End)

EXAMPLE

Some solutions for n=3:

..0..1..1....0..0..0....1..1..1....1..1..1....0..0..1....1..1..1....0..0..1

..0..0..0....0..0..0....0..1..1....0..1..1....0..1..1....0..0..1....0..0..1

..0..0..0....0..0..1....1..1..1....0..0..0....0..0..0....0..0..0....0..0..0

..0..0..0....0..0..1....1..1..1....0..0..0....0..0..0....0..0..1....0..1..1

..0..1..1....0..1..1....0..0..1....0..1..1....0..0..1....0..0..1....1..1..1

..0..0..0....0..0..1....0..0..0....0..0..1....1..1..1....0..0..1....0..0..0

CROSSREFS

Cf. A223949.

Sequence in context: A164337 A161860 A195249 * A224137 A016899 A250364

Adjacent sequences:  A223950 A223951 A223952 * A223954 A223955 A223956

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 29 2013

STATUS

approved

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Last modified November 29 14:50 EST 2021. Contains 349416 sequences. (Running on oeis4.)