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A220618 Number of ways to reciprocally link elements of an nX5 array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor 1
8, 317, 9176, 282777, 8608738, 262680517, 8011414792, 244357686173, 7453056468816, 227323314349577, 6933510501158596, 211476640729594693, 6450176661330373022, 196734631145079828705, 6000535646826871036976 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A220621

LINKS

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

FORMULA

Empirical: a(n) = 38*a(n-1) -189*a(n-2) -1434*a(n-3) +6910*a(n-4) -3882*a(n-5) -9380*a(n-6) +9742*a(n-7) -477*a(n-8) -1476*a(n-9) +125*a(n-10)

EXAMPLE

Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)

..0..0..9..9..0....0..0..0..6..4....6..4..7..0..0....0..0..6..4..0

..0..7..0..1..1....0..6..4..9..0....9..3..0..9..0....9..6..4..6..4

..3..0..6..4..0....0..0..0..0..1....0..1..0..0..1....0..1..0..0..0

CROSSREFS

Sequence in context: A081980 A264661 A231781 * A221721 A079504 A282621

Adjacent sequences:  A220615 A220616 A220617 * A220619 A220620 A220621

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 17 2012

STATUS

approved

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Last modified May 16 22:37 EDT 2022. Contains 353724 sequences. (Running on oeis4.)