login
A302954
Number of 3Xn 0..1 arrays with every element equal to 1, 2, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
0, 11, 86, 519, 3626, 26167, 185810, 1317541, 9353154, 66404553, 471405566, 3346494089, 23756835310, 168650322345, 1197251824916, 8499313431065, 60336790015098, 428332035511083, 3040737367321452, 21586253123647687
OFFSET
1,2
COMMENTS
Row 3 of A302953.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +15*a(n-2) +37*a(n-3) +80*a(n-4) +68*a(n-5) +26*a(n-6) +5*a(n-7) for n>9
EXAMPLE
Some solutions for n=5
..0..0..0..1..1. .0..0..0..0..0. .0..1..0..0..0. .0..0..1..1..0
..0..0..0..0..0. .0..0..1..1..1. .1..0..1..0..1. .1..1..0..0..1
..1..1..0..1..1. .0..0..0..1..1. .0..1..1..1..0. .1..0..1..0..0
CROSSREFS
Cf. A302953.
Sequence in context: A344480 A320940 A012794 * A014917 A080962 A243879
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 16 2018
STATUS
approved