A223422 3-level binary fanout graph coloring a rectangular array: number of nX7 0..6 arrays where 0..6 label nodes of a graph with edges 0,1 1,3 1,4 0,2 2,5 2,6 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph

416, 18464, 1033328, 50097024, 2844612736, 139114196992, 7939011165696, 389154431528960, 22244132907945984, 1091144538683604992, 62401586754017968128, 3061680318925083639808, 175122575873489263525888

Offset

1,1

Comments

Column 7 of A223423

Links

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

Formula

Empirical: a(n) = 4144*a(n-2) -4233568*a(n-4) +1423446528*a(n-6) -216571051008*a(n-8) +17498453049344*a(n-10) -823976834072576*a(n-12) +23806610175950848*a(n-14) -433179956841807872*a(n-16) +5014404982720430080*a(n-18) -36922985056839925760*a(n-20) +171827754849678655488*a(n-22) -499189157380780720128*a(n-24) +886405116754355290112*a(n-26) -927140136557417070592*a(n-28) +537868927709415997440*a(n-30) -158472804425401368576*a(n-32) +20342196566879109120*a(n-34) -788129934789836800*a(n-36)

Example

Some solutions for n=3
..0..1..4..1..3..1..3....0..1..0..1..0..2..6....0..1..3..1..4..1..0
..1..3..1..3..1..3..1....1..0..2..0..2..0..2....1..0..1..3..1..0..1
..3..1..3..1..3..1..4....3..1..0..2..5..2..0....0..1..3..1..3..1..0

Crossrefs

Sequence in context: A249006 A249471 A246897 * A239191 A324613 A202527

Adjacent sequences: A223419 A223420 A223421 * A223423 A223424 A223425

Keyword

nonn

Author

R. H. Hardin Mar 20 2013

Status

approved