The On-Line Encyclopedia of Integer Sequences (OEIS)

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A223920

Number of 3Xn 0..2 arrays with rows and antidiagonals unimodal and columns nondecreasing
(history; published version)

#4 by R. H. Hardin at Fri Mar 29 07:21:00 EDT 2013

STATUS

editing

approved

#3 by R. H. Hardin at Fri Mar 29 07:20:55 EDT 2013

LINKS

R. H. Hardin, <a href="/A223920/b223920.txt">Table of n, a(n) for n = 1..210</a>

#2 by R. H. Hardin at Fri Mar 29 07:20:39 EDT 2013

NAME

allocated for R. H. Hardin

Number of 3Xn 0..2 arrays with rows and antidiagonals unimodal and columns nondecreasing

DATA

10, 100, 666, 3311, 13347, 45988, 140236, 387671, 988447, 2354539, 5291652, 11307388, 23115717, 45438234, 86243127, 158615577, 283521156, 493809754, 839915122, 1397838161, 2280164963, 3651068140, 5746477482, 8900889311

OFFSET

1,1

COMMENTS

Row 3 of A223918

FORMULA

Empirical: a(n) = (1/19160064)*n^12 + (5/3193344)*n^11 + (1627/43545600)*n^10 + (257/483840)*n^9 + (2309/414720)*n^8 + (19319/483840)*n^7 + (8701321/43545600)*n^6 + (971137/1451520)*n^5 + (3369229/2177280)*n^4 + (294809/120960)*n^3 + (652717/237600)*n^2 + (521/385)*n + 1

EXAMPLE

Some solutions for n=3

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

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

..2..2..1....1..2..2....1..2..2....2..2..2....1..2..2....1..1..2....1..1..2

KEYWORD

allocated

nonn

AUTHOR

R. H. Hardin Mar 29 2013

STATUS

approved

editing

#1 by R. H. Hardin at Fri Mar 29 07:09:24 EDT 2013

NAME

allocated for R. H. Hardin

KEYWORD

allocated

STATUS

approved