A281655 Number of 3Xn 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

0, 46, 985, 7986, 67884, 519656, 3804074, 27188104, 190081944, 1307551136, 8883115770, 59735869460, 398338301812, 2637611297824, 17360607113512, 113677820297300, 741027989329060, 4811486509126868, 31131965964391810

Offset

1,2

Comments

Row 3 of A281653.

Links

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

Formula

Empirical: a(n) = 12*a(n-1) -44*a(n-2) +106*a(n-3) -394*a(n-4) +558*a(n-5) -1815*a(n-6) +1258*a(n-7) -3975*a(n-8) +1226*a(n-9) -3167*a(n-10) -2598*a(n-11) +4765*a(n-12) +1286*a(n-13) -710*a(n-14) +3446*a(n-15) +4320*a(n-16) -2580*a(n-17) -2693*a(n-18) +836*a(n-19) -456*a(n-20) -1676*a(n-21) -92*a(n-22) +1000*a(n-23) +316*a(n-24) -160*a(n-25) -64*a(n-26) for n>29

Example

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

Crossrefs

Cf. A281653.

Sequence in context: A078427 A002138 A205495 * A280280 A010962 A057465

Adjacent sequences: A281652 A281653 A281654 * A281656 A281657 A281658

Keyword

nonn

Author

R. H. Hardin, Jan 26 2017

Status

approved