A183651 Number of (n+1) X 9 0..4 arrays with every 2 X 2 subblock summing to 8.

2517805, 3771425, 6663805, 13653545, 31446805, 79273025, 214853005, 618704345, 1876491205, 5952232625, 19633254205, 67026931145, 235915631605, 853194728225, 3160908007405, 11963696693945, 46149432308005, 181066087559825, 721415896712605, 2915499344152745, 11942707793560405

Offset

1,1

Links

Paolo Xausa, Table of n, a(n) for n = 1..1000

Christian Krause, Proof of formula, Jun 13 2026.

Index entries for linear recurrences with constant coefficients, signature (15,-85,225,-274,120).

Formula

a(n) = 5*5^n + 2040*4^n + 55980*3^n + 446580*2^n + 1448520. - Christian Krause, Jun 13 2026

Example

Some solutions for 3X9
..0..0..0..2..2..0..3..3..3....1..0..0..4..2..2..1..3..0
..4..4..4..2..2..4..1..1..1....3..4..4..0..2..2..3..1..4
..0..0..0..2..2..0..3..3..3....1..0..0..4..2..2..1..3..0

Mathematica

A183651[n_] := 5*5^n + 2040*4^n + 55980*3^n + 446580*2^n + 1448520;
Array[A183651, 25] (* Paolo Xausa, Jun 16 2026 *)

Crossrefs

Column 8 of A183652.

Sequence in context: A234910 A233927 A157769 * A259628 A251857 A096557

Adjacent sequences: A183648 A183649 A183650 * A183652 A183653 A183654

Keyword

nonn,easy

Author

R. H. Hardin, Jan 06 2011

Extensions

a(7)-a(21) from Christian Krause, Jun 13 2026

Status

approved