The On-Line Encyclopedia of Integer Sequences (OEIS)

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A225013

Number of 6Xn 0..1 arrays with rows unimodal and columns nondecreasing
(history; published version)

#4 by R. H. Hardin at Tue Apr 23 21:56:06 EDT 2013

STATUS

editing

approved

#3 by R. H. Hardin at Tue Apr 23 21:56:03 EDT 2013

LINKS

R. H. Hardin, <a href="/A225013/b225013.txt">Table of n, a(n) for n = 1..210</a>

#2 by R. H. Hardin at Tue Apr 23 21:55:46 EDT 2013

NAME

allocated for R. H. Hardin

Number of 6Xn 0..1 arrays with rows unimodal and columns nondecreasing

DATA

7, 49, 252, 1036, 3612, 11088, 30738, 78354, 186142, 416394, 884236, 1794196, 3497248, 6577474, 11980667, 21201211, 36548573, 61520899, 101320712, 163556776, 259187048, 403770544, 619111172, 935394436, 1393938716, 2050706932

OFFSET

1,1

COMMENTS

Row 6 of A225010

FORMULA

Empirical: a(n) = (1/479001600)*n^12 + (1/7257600)*n^11 + (187/43545600)*n^10 + (13/161280)*n^9 + (14671/14515200)*n^8 + (3043/345600)*n^7 + (2380201/43545600)*n^6 + (347911/1451520)*n^5 + (8129699/10886400)*n^4 + (923183/604800)*n^3 + (913741/415800)*n^2 + (49/40)*n + 1

EXAMPLE

Some solutions for n=3

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

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

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

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

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

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

KEYWORD

allocated

nonn

AUTHOR

R. H. Hardin Apr 23 2013

STATUS

approved

editing

#1 by R. H. Hardin at Tue Apr 23 21:47:07 EDT 2013

NAME

allocated for R. H. Hardin

KEYWORD

allocated

STATUS

approved