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A250437 Number of (n+1)X(2+1) 0..2 arrays with nondecreasing sum of every two consecutive values in every row and column 1
324, 2160, 14400, 60000, 250000, 787500, 2480625, 6482700, 16941456, 38723328, 88510464, 182891520, 377913600, 721710000, 1378265625, 2470668750, 4428902500, 7537186800, 12826921536, 20901168288, 34057964304, 53488469580, 84004327225 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A250443

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +10*a(n-2) -22*a(n-3) -44*a(n-4) +110*a(n-5) +110*a(n-6) -330*a(n-7) -165*a(n-8) +660*a(n-9) +132*a(n-10) -924*a(n-11) +924*a(n-13) -132*a(n-14) -660*a(n-15) +165*a(n-16) +330*a(n-17) -110*a(n-18) -110*a(n-19) +44*a(n-20) +22*a(n-21) -10*a(n-22) -2*a(n-23) +a(n-24)

Empirical for n mod 2 = 0: a(n) = (1/2359296)*n^12 + (7/294912)*n^11 + (355/589824)*n^10 + (449/49152)*n^9 + (4541/49152)*n^8 + (1007/1536)*n^7 + (123317/36864)*n^6 + (113887/9216)*n^5 + (9439/288)*n^4 + (5837/96)*n^3 + (1197/16)*n^2 + (219/4)*n + 18

Empirical for n mod 2 = 1: a(n) = (1/2359296)*n^12 + (7/294912)*n^11 + (713/1179648)*n^10 + (2729/294912)*n^9 + (223799/2359296)*n^8 + (101131/147456)*n^7 + (2115031/589824)*n^6 + (2014145/147456)*n^5 + (88753375/2359296)*n^4 + (7180625/98304)*n^3 + (12440625/131072)*n^2 + (2428125/32768)*n + (6890625/262144)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

CROSSREFS

Sequence in context: A202486 A305070 A229538 * A064197 A233639 A203374

Adjacent sequences:  A250434 A250435 A250436 * A250438 A250439 A250440

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 22 2014

STATUS

approved

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Last modified December 11 23:44 EST 2019. Contains 329945 sequences. (Running on oeis4.)