A251974 - OEIS

%I #6 Dec 12 2014 20:17:47

%S 256,1600,1600,10000,20000,10000,40000,250000,250000,40000,160000,

%T 1750000,6250000,1750000,160000,490000,12250000,76562500,76562500,

%U 12250000,490000,1500625,60025000,937890625,1500625000,937890625

%N T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with nondecreasing sum of every two consecutive values in every row and column

%C Table starts

%C .....256......1600.......10000.........40000..........160000............490000

%C ....1600.....20000......250000.......1750000........12250000..........60025000

%C ...10000....250000.....6250000......76562500.......937890625........7353062500

%C ...40000...1750000....76562500....1500625000.....29412250000......345888060000

%C ..160000..12250000...937890625...29412250000....922368160000....16270574342400

%C ..490000..60025000..7353062500..345888060000..16270574342400...410018473428480

%C .1500625.294122500.57648010000.4067643585600.287012931399936.10332465530397696

%H R. H. Hardin, <a href="/A251974/b251974.txt">Table of n, a(n) for n = 1..160</a>

%F Empirical for column k:

%F k=1: [linear recurrence of order 24; also a polynomial of degree 12 plus a quasipolynomial of degree 10 with period 2]

%F k=2: [order 36; also a polynomial of degree 18 plus a quasipolynomial of degree 16 with period 2]

%F k=3: [order 48; also a polynomial of degree 24 plus a quasipolynomial of degree 22 with period 2]

%F k=4: [polynomial of degree 30 plus a quasipolynomial of degree 28 with period 2]

%e Some solutions for n=2 k=4

%e ..0..0..0..1..0....1..1..1..1..2....1..0..1..1..1....0..0..0..0..0

%e ..1..0..1..0..3....1..0..2..0..2....0..0..0..0..2....0..0..0..0..0

%e ..2..1..2..1..2....2..2..2..2..3....1..3..2..3..2....2..1..2..2..3

%Y Column 1 is A250429

%Y Column 3 is A250440

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_, Dec 12 2014