A232077 - OEIS

A232077

Number of (1+1) X (n+1) 0..1 arrays with every element equal to some horizontal, diagonal or antidiagonal neighbor, with top left element zero.

3, 15, 46, 161, 601, 2208, 8053, 29415, 107534, 393061, 1436589, 5250624, 19190841, 70141747, 256364934, 937002409, 3424702513, 12517136672, 45749581901, 167212702063, 611155044830, 2233744710845, 8164238313221, 29839930638080

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OFFSET

1,1

COMMENTS

Row 1 of A232076.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) + a(n-2) + 4*a(n-3) + 4*a(n-4).

Empirical g.f.: x*(1 + 2*x)*(3 - 2*x^2) / (1 - 3*x - x^2 - 4*x^3 - 4*x^4). - Colin Barker, Mar 19 2018

EXAMPLE

Some solutions for n=7:

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

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

CROSSREFS

Cf. A232076.

Sequence in context: A331505 A088108 A226030 * A163383 A296799 A328111

Adjacent sequences: A232074 A232075 A232076 * A232078 A232079 A232080

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 17 2013

STATUS

approved