A281248 Number of nX3 0..2 arrays with no element equal to more than one of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 12, 443, 8489, 105368, 1113148, 10598099, 94350141, 800540848, 6552843938, 52163574440, 406096164959, 3104415588852, 23374506589595, 173753114036173, 1277461524990825, 9303058981853048, 67186844864693416, 481669905249353054

Offset

1,2

Comments

Column 3 of A281251.

Links

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

Formula

Empirical: a(n) = 14*a(n-1) -37*a(n-2) -137*a(n-3) +133*a(n-4) +1003*a(n-5) +3804*a(n-6) +5187*a(n-7) -2352*a(n-8) -9604*a(n-9) -8788*a(n-10) +20660*a(n-11) +73716*a(n-12) +13836*a(n-13) -107898*a(n-14) -90512*a(n-15) +29977*a(n-16) +283636*a(n-17) +190689*a(n-18) -510519*a(n-19) -322065*a(n-20) +553505*a(n-21) +160238*a(n-22) -387019*a(n-23) +48576*a(n-24) +108354*a(n-25) -163512*a(n-26) -22652*a(n-27) +75376*a(n-28) +6952*a(n-29) +12160*a(n-30) +24352*a(n-31) +7936*a(n-32) +2432*a(n-33) +2048*a(n-34) +512*a(n-35) for n>45

Example

Some solutions for n=4
..0..1..2. .0..1..0. .0..1..0. .0..1..2. .0..0..1. .0..0..1. .0..1..0
..0..2..1. .0..2..0. .1..0..1. .2..0..1. .1..1..2. .1..1..2. .0..0..2
..1..2..2. .0..1..2. .0..1..2. .2..0..1. .2..2..0. .0..2..0. .2..1..2
..2..1..0. .0..2..0. .0..2..1. .1..0..1. .1..1..0. .1..2..0. .1..0..0

Crossrefs

Cf. A281251.

Sequence in context: A159534 A303922 A246502 * A338960 A195616 A126603

Adjacent sequences: A281245 A281246 A281247 * A281249 A281250 A281251

Keyword

nonn

Author

R. H. Hardin, Jan 18 2017

Status

approved