A250657 - OEIS

A250657

Number of (3+1)X(n+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction

39, 70, 109, 156, 211, 274, 345, 424, 511, 606, 709, 820, 939, 1066, 1201, 1344, 1495, 1654, 1821, 1996, 2179, 2370, 2569, 2776, 2991, 3214, 3445, 3684, 3931, 4186, 4449, 4720, 4999, 5286, 5581, 5884, 6195, 6514, 6841, 7176, 7519, 7870, 8229, 8596, 8971

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OFFSET

1,1

COMMENTS

Row 3 of A250656

LINKS

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

FORMULA

Empirical: a(n) = 4*n^2 + 19*n + 16

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A046448 A249701 A039467 * A243577 A253153 A044105

Adjacent sequences: A250654 A250655 A250656 * A250658 A250659 A250660

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 26 2014

STATUS

approved