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A263551 Number of (n+1)X(1+1) 0..4 arrays with each row and column divisible by 7, read as a base-5 number with top and left being the most significant digits. 1
4, 10, 40, 148, 592, 2344, 9376, 37456, 149824, 599200, 2396800, 9587008, 38348032, 153391744, 613566976, 2454267136, 9817068544, 39268272640, 157073090560, 628292359168, 2513169436672, 10052677740544, 40210710962176 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A263558.

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) +2*a(n-2) -8*a(n-3).

Empirical: G.f.: -2*x*(-2+3*x+4*x^2) / ( (4*x-1)*(2*x^2-1) ). - R. J. Mathar, Nov 03 2015

EXAMPLE

Some solutions for n=4

..4..1....0..0....4..1....1..2....4..1....4..1....2..4....1..2....0..0....2..4

..2..4....4..1....1..2....1..2....4..1....2..4....4..1....0..0....4..1....0..0

..0..0....1..2....2..4....0..0....4..1....2..4....4..1....2..4....2..4....4..1

..0..0....1..2....4..1....4..1....0..0....0..0....2..4....0..0....4..1....0..0

..1..2....2..4....0..0....0..0....1..2....0..0....2..4....4..1....4..1....1..2

CROSSREFS

Cf. A263558.

Sequence in context: A149211 A149212 A223160 * A007173 A222367 A220817

Adjacent sequences:  A263548 A263549 A263550 * A263552 A263553 A263554

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 21 2015

STATUS

approved

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Last modified December 9 22:27 EST 2019. Contains 329880 sequences. (Running on oeis4.)