

A233402


Number of (n+1) X (1+1) 0..2 arrays with row and column sums nondecreasing, and no adjacent elements equal.


1



9, 11, 22, 24, 41, 42, 66, 65, 97, 93, 134, 126, 177, 164, 226, 207, 281, 255, 342, 308, 409, 366, 482, 429, 561, 497, 646, 570, 737, 648, 834, 731, 937, 819, 1046, 912, 1161, 1010, 1282, 1113, 1409, 1221, 1542, 1334, 1681, 1452, 1826, 1575, 1977, 1703, 2134
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OFFSET

1,1


LINKS

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


FORMULA

Empirical: a(n) = 3*a(n2)  3*a(n4) + a(n6).
Conjectures from Colin Barker, Oct 11 2018: (Start)
G.f.: x*(9 + 11*x  5*x^2  9*x^3 + 2*x^4 + 3*x^5) / ((1  x)^3*(1 + x)^3).
a(n) = (62  14*(1)^n + (506*(1)^n)*n + (11+(1)^(1+n))*n^2) / 16.
(End)


EXAMPLE

Some solutions for n=5:
..2..0....0..1....0..1....1..0....0..1....0..2....0..1....1..0....1..0....0..1
..0..2....1..0....1..0....0..2....1..0....2..0....1..0....0..1....0..1....1..0
..2..0....0..2....0..2....2..0....0..1....0..2....0..2....1..0....2..0....2..1
..0..2....2..0....2..0....1..2....1..0....2..1....2..1....0..2....0..2....1..2
..2..1....0..2....0..2....2..1....2..1....1..2....1..2....2..1....2..1....2..1
..1..2....2..1....2..0....1..2....1..2....2..1....2..1....1..2....1..2....1..2


CROSSREFS

Column 1 of A233408.
Sequence in context: A022323 A106525 A103510 * A276406 A130730 A153697
Adjacent sequences: A233399 A233400 A233401 * A233403 A233404 A233405


KEYWORD

nonn


AUTHOR

R. H. Hardin, Dec 09 2013


STATUS

approved



