A305477 - OEIS

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A305477

Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 6 or 8 king-move adjacent elements, with upper left element zero.

3, 7, 10, 21, 40, 70, 125, 231, 419, 752, 1365, 2482, 4488, 8121, 14729, 26689, 48322, 87545, 158636, 287360, 520537, 943067, 1708503, 3095024, 5606953, 10157742, 18401740, 33336465, 60392685, 109407857, 198203346, 359065917, 650486008

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

OFFSET

1,1

COMMENTS

Column 3 of A305482.

LINKS

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

Simon Plouffe, Conjectures of the OEIS, as of June 20, 2018.

FORMULA

Empirical: a(n) = a(n-1) +3*a(n-3) -2*a(n-6) for n>9.

Empirical: -x*(-2*x^8-2*x^6-2*x^4+2*x^3+3*x^2+4*x+3)/(-2*x^6+3*x^3+x-1). - Simon Plouffe, Jun 20 2018

EXAMPLE