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A213963 Number of 3X3 0..n matrices with row and column 1..3 having sum <= i*n 1
138, 3186, 32060, 199735, 909900, 3323712, 10301232, 28115505, 69342790, 157454154, 333771516, 667605263, 1270560760, 2316187440, 4066346688, 6905893425, 11387501154, 18288711250, 28683554460, 44031375927, 66285794564 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A213962

LINKS

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

FORMULA

Empirical: a(n) = (n+3) *(n+2) *(449*n^5+3038*n^4+7759*n^3+9790*n^2+6264*n+1680) *(1+n)^2/10080.

EXAMPLE

Some solutions for n=4

..2..0..0....4..0..0....4..0..0....2..0..0....0..3..0....2..2..0....1..3..0

..0..0..0....0..1..2....0..2..4....0..2..2....2..1..2....2..2..2....1..4..2

..1..4..2....0..0..1....0..3..3....0..3..1....2..4..0....0..4..3....0..1..0

CROSSREFS

Sequence in context: A260133 A317579 A281592 * A279964 A163693 A089518

Adjacent sequences:  A213960 A213961 A213962 * A213964 A213965 A213966

KEYWORD

nonn

AUTHOR

R. H. Hardin Jun 28 2012

STATUS

approved

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Last modified December 9 06:07 EST 2021. Contains 349627 sequences. (Running on oeis4.)