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A203780 Number of (n+1) X 2 0..3 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) such that rows of b(i,j) and columns of c(i,j) are lexicographically nondecreasing. 1
90, 565, 3352, 18332, 93578, 452825, 2103364, 9466880, 41577146, 179125413, 760104672, 3186880092, 13234285226, 54540491961, 223403152908, 910633752400, 3697500096250, 14966619506101, 60431546809704, 243527111738236 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A203787.

LINKS

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

FORMULA

Empirical: a(n) = 18*a(n-1) -139*a(n-2) +604*a(n-3) -1627*a(n-4) +2818*a(n-5) -3141*a(n-6) +2176*a(n-7) -852*a(n-8) +144*a(n-9).

Empirical g.f.: x*(90 - 1055*x + 5692*x^2 - 17829*x^3 + 34700*x^4 - 42404*x^5 + 31552*x^6 - 13056*x^7 + 2304*x^8) / ((1 - x)^4*(1 - 2*x)^2*(1 - 3*x)^2*(1 - 4*x)). - Colin Barker, Jun 04 2018

EXAMPLE

Some solutions for n=4:

..0..2....1..3....1..1....2..1....1..2....3..1....0..3....1..0....0..1....2..0

..1..3....1..3....1..1....2..3....1..3....1..3....0..3....0..1....3..2....0..2

..2..2....3..1....2..2....2..3....1..3....1..3....1..2....0..3....2..3....1..1

..1..3....1..3....2..3....2..3....3..2....1..3....1..3....1..2....3..2....3..1

..2..2....1..3....2..3....2..3....2..3....3..2....3..3....1..2....2..3....1..3

CROSSREFS

Cf. A203787.

Sequence in context: A156738 A211446 A203787 * A295982 A065949 A224541

Adjacent sequences:  A203777 A203778 A203779 * A203781 A203782 A203783

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 05 2012

STATUS

approved

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Last modified July 20 01:17 EDT 2019. Contains 325168 sequences. (Running on oeis4.)