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A200984 Number of nX2 0..4 arrays with every row and column nondecreasing rightwards and downwards, and the number of instances of each value within one of each other 1
10, 10, 20, 79, 21, 226, 157, 227, 678, 120, 1272, 789, 1015, 2697, 404, 4232, 2484, 3008, 7496, 1025, 10650, 6050, 7060, 16895, 2181, 22530, 12525, 14255, 33174, 4116, 42336, 23177, 25907, 59073, 7120, 72992, 39504, 43560, 97792, 11529, 117882, 63234 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A200990

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-5) -10*a(n-10) +10*a(n-15) -5*a(n-20) +a(n-25)

Subsequences for n modulo 5 = 1,2,3,4,0:

p=(n+4)/5: a(n) = (115/6)*p^4 - 11*p^3 + (11/6)*p^2

q=(n+3)/5: a(n) = (115/12)*q^4 + (1/2)*q^3 - (1/12)*q^2

r=(n+2)/5: a(n) = (115/12)*r^4 + (49/6)*r^3 + (23/12)*r^2 + (1/3)*r

s=(n+1)/5: a(n) = (115/6)*s^4 + 35*s^3 + (125/6)*s^2 + 4*s

t=(n+0)/5: a(n) = (23/12)*t^4 + (37/6)*t^3 + (91/12)*t^2 + (13/3)*t + 1

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A076817 A324494 A344104 * A299576 A185993 A109051

Adjacent sequences:  A200981 A200982 A200983 * A200985 A200986 A200987

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 25 2011

STATUS

approved

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Last modified November 26 20:36 EST 2021. Contains 349343 sequences. (Running on oeis4.)