A251803 Number of (3+1)X(n+1) 0..3 arrays with no 2X2 subblock having x11-x00 less than x10-x01

19269, 724300, 17195593, 294088336, 3934266515, 43510308650, 413630526506, 3478117057808, 26433809155056, 184631083973492, 1200862969509714, 7350360178000790, 42705102555064986, 237181196199079904

Offset

1,1

Comments

Row 3 of A251801

Links

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

Formula

Empirical: a(n) = 70*a(n-1) -2375*a(n-2) +52042*a(n-3) -827990*a(n-4) +10195132*a(n-5) -101124322*a(n-6) +830421108*a(n-7) -5758451859*a(n-8) +34223487178*a(n-9) -176332070653*a(n-10) +794779755110*a(n-11) -3156457476820*a(n-12) +11109873120920*a(n-13) -34818233254780*a(n-14) +97527763758712*a(n-15) -244892909297175*a(n-16) +552543768062970*a(n-17) -1122181309818449*a(n-18) +2053995521193590*a(n-19) -3390759101221990*a(n-20) +5049772850347484*a(n-21) -6783271969135666*a(n-22) +8213149434578420*a(n-23) -8953247189169461*a(n-24) +8772430272272310*a(n-25) -7708025280163467*a(n-26) +6055906423103258*a(n-27) -4238615566223888*a(n-28) +2630732733430288*a(n-29) -1439628171650384*a(n-30) +689679083321824*a(n-31) -286667447021696*a(n-32) +102211164419072*a(n-33) -30802911196416*a(n-34) +7693171914240*a(n-35) -1549479297024*a(n-36) +241805316096*a(n-37) -27432235008*a(n-38) +2012553216*a(n-39) -71663616*a(n-40)

Example

Some solutions for n=1
..0..3....1..2....3..1....3..2....2..1....1..3....0..0....0..0....3..2....0..3
..2..1....0..0....0..2....0..1....1..2....3..3....3..3....2..2....2..3....0..0
..2..3....0..1....0..0....3..3....0..3....1..3....0..3....2..3....0..3....0..3
..0..1....0..3....2..2....0..2....2..0....3..2....3..3....2..1....2..0....1..3

Crossrefs

Sequence in context: A323966 A035925 A186875 * A184667 A280555 A031831

Adjacent sequences: A251800 A251801 A251802 * A251804 A251805 A251806

Keyword

nonn

Author

R. H. Hardin, Dec 09 2014

Status

approved