A300493 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A300493

Number of nX3 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

4, 18, 52, 143, 412, 1225, 3699, 11243, 34012, 102446, 307967, 926094, 2787783, 8398551, 25307489, 76250370, 229695945, 691863018, 2083934202, 6277172983, 18908580942, 56958622146, 171576895601, 516838549210, 1556857505073

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 3 of A300498.

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) -17*a(n-2) +12*a(n-3) +23*a(n-4) -46*a(n-5) +4*a(n-6) +24*a(n-7) +20*a(n-8) -52*a(n-9) +5*a(n-10) +53*a(n-11) +22*a(n-12) -47*a(n-13) -86*a(n-14) +78*a(n-15) +89*a(n-16) +84*a(n-17) -64*a(n-18) -22*a(n-19) -35*a(n-20) +15*a(n-21) +a(n-22) +4*a(n-23) -a(n-24) for n>25

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A300498.

Sequence in context: A092349 A027659 A059133 * A300876 A301486 A284607

Adjacent sequences: A300490 A300491 A300492 * A300494 A300495 A300496

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 07 2018

STATUS

approved