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A250989 Number of (n+1)X(3+1) 0..2 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction 1
646, 4007, 21955, 111175, 542834, 2592734, 12238954, 57388086, 268220043, 1251995646, 5843762848, 27293152949, 127596737815, 597184294909, 2798100377112, 13124265846109, 61616682850586, 289522081723318 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A250994

LINKS

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

FORMULA

Empirical: a(n) = 25*a(n-1) -263*a(n-2) +1465*a(n-3) -4208*a(n-4) +2752*a(n-5) +20591*a(n-6) -63149*a(n-7) +39306*a(n-8) +127182*a(n-9) -234935*a(n-10) -16967*a(n-11) +341508*a(n-12) -162216*a(n-13) -227787*a(n-14) +169273*a(n-15) +82343*a(n-16) -69183*a(n-17) -19686*a(n-18) +10818*a(n-19) +3132*a(n-20)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

CROSSREFS

Sequence in context: A057942 A230488 A228575 * A187434 A046020 A108821

Adjacent sequences:  A250986 A250987 A250988 * A250990 A250991 A250992

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 29 2014

STATUS

approved

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Last modified May 7 10:02 EDT 2021. Contains 343649 sequences. (Running on oeis4.)