A198509 Number of 2nX4 0..4 arrays with values 0..4 introduced in row major order and each element unequal to exactly two horizontal and vertical neighbors

59, 4666, 308854, 23016128, 1768050096, 137433138206, 10767346425686, 846703466364788, 66715358024129644, 5262276771966640650, 415296502306889789762, 32784348340670740616160, 2588447317141729017555864

Offset

1,1

Comments

Column 2 of A198511

Links

R. H. Hardin, Table of n, a(n) for n = 1..179

Formula

Empirical: a(n) = 168*a(n-1) -9635*a(n-2) +230508*a(n-3) -1868458*a(n-4) -8029700*a(n-5) -28347702*a(n-6) +7358565368*a(n-7) -118460559973*a(n-8) +848136638992*a(n-9) -2704417624327*a(n-10) -758800108020*a(n-11) +26654251234560*a(n-12) +33477385996812*a(n-13) -778269041202000*a(n-14) +1691040379701264*a(n-15) +5723652909363264*a(n-16) -22555014434827584*a(n-17) -25385900061199616*a(n-18) +137722671189043200*a(n-19) +134897275429925888*a(n-20) -499905738358480896*a(n-21) -804105697954512896*a(n-22) +1173387177266905088*a(n-23) +2723824778237706240*a(n-24) -1319488323495919616*a(n-25) -4574511335676575744*a(n-26) +529114613380284416*a(n-27) +2540311664813670400*a(n-28)

Example

Some solutions for n=3
..0..1..1..0....0..1..0..2....0..1..1..2....0..1..1..0....0..1..1..0
..2..3..3..4....2..1..0..0....1..3..3..1....1..2..2..3....2..3..3..1
..2..3..3..4....2..1..1..1....1..3..3..1....1..2..2..3....2..3..3..1
..4..4..4..2....0..3..3..3....2..2..2..2....2..3..3..2....0..4..4..3
..3..3..4..2....0..3..4..4....0..0..1..1....2..3..3..2....0..4..4..3
..0..3..4..3....2..3..4..2....2..0..1..0....4..0..0..1....2..1..1..0

Crossrefs

Sequence in context: A119886 A135649 A278367 * A258269 A094489 A235215

Adjacent sequences: A198506 A198507 A198508 * A198510 A198511 A198512

Keyword

nonn

Author

R. H. Hardin Oct 25 2011

Status

approved