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A204650 Number of (n+1) X 8 0..1 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) nondecreasing in column and row directions, respectively. 1
216, 283, 637, 1478, 3261, 6780, 13314, 24862, 44426, 76378, 126906, 204583, 321038, 491781, 737163, 1083525, 1564519, 2222657, 3111073, 4295556, 5856841, 7893218, 10523448, 13890048, 18162936, 23543500, 30269084, 38617957, 48914760, 61536499 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A204651.

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) - 27*a(n-2) + 48*a(n-3) - 42*a(n-4) + 42*a(n-6) - 48*a(n-7) + 27*a(n-8) - 8*a(n-9) + a(n-10) for n > 15.

Empirical g.f.: x*(216 - 1445*x + 4205*x^2 - 6345*x^3 + 4124*x^4 + 1908*x^5 - 6141*x^6 + 5440*x^7 - 2472*x^8 + 519*x^9 + 27*x^10 - 28*x^11 - 24*x^12 + 24*x^13 - 6*x^14) / ((1 - x)^9*(1 + x)). - Colin Barker, Jun 08 2018

EXAMPLE

Some solutions for n=5:

  1 0 1 0 1 0 0 1       0 0 0 0 0 0 0 0       0 0 0 0 0 0 0 1

  0 1 0 1 0 1 1 1       0 0 0 0 0 0 0 1       0 0 0 0 0 0 0 1

  1 0 1 0 1 1 1 1       0 0 0 0 0 0 0 1       0 0 0 0 0 0 1 1

  0 1 0 1 1 1 1 1       0 0 0 1 1 1 1 1       0 0 0 0 0 1 1 1

  1 0 1 1 1 1 1 1       1 1 1 1 1 1 1 1       0 0 0 0 0 1 1 1

  0 1 1 1 1 1 1 1       1 1 1 1 1 1 1 1       1 1 1 1 1 1 1 1

CROSSREFS

Cf. A204651.

Sequence in context: A001239 A184088 A205191 * A115430 A278976 A179419

Adjacent sequences:  A204647 A204648 A204649 * A204651 A204652 A204653

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 17 2012

STATUS

approved

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Last modified August 4 10:03 EDT 2021. Contains 346446 sequences. (Running on oeis4.)