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A301993 Number of n X n 0..1 arrays with every element equal to 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero. 0
0, 2, 5, 74, 2856, 100176, 15243860, 3267873712, 1423142192108, 1493258497764034, 2656316754272813006, 10809582885066864547012, 85481211759186744525328998, 1368540960166632565900365694716 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A301999.

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

Some solutions for n=5

..0..0..1..1..0. .0..0..1..1..0. .0..0..1..1..0. .0..0..1..1..1

..0..0..1..0..1. .0..1..0..0..1. .0..0..1..0..0. .0..1..0..1..0

..0..0..1..1..1. .1..1..1..1..1. .1..1..1..0..0. .1..0..0..0..0

..0..1..1..0..1. .0..0..1..1..1. .1..1..1..1..1. .1..1..0..1..0

..0..0..0..1..1. .0..0..1..0..0. .1..0..0..0..0. .1..0..1..0..0

CROSSREFS

Cf. A301999.

Sequence in context: A042693 A328746 A172037 * A128297 A183291 A254405

Adjacent sequences:  A301990 A301991 A301992 * A301994 A301995 A301996

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 30 2018

STATUS

approved

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Last modified December 5 05:51 EST 2020. Contains 338944 sequences. (Running on oeis4.)