A183671 Number of (n+1) X 9 0..6 arrays with every 2 X 2 subblock summing to 12.

64979929, 129463663, 311907001, 870960607, 2719942729, 9273350863, 33957855001, 131986793407, 539627127529, 2304481894063, 10222025955001, 46883036386207, 221508157640329, 1074751240133263, 5341087960167001, 27125675410779007, 140513487311641129, 741148037371428463

Offset

1,1

Links

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

Christian Krause, Proof of formula, Jun 14 2026.

Index entries for linear recurrences with constant coefficients, signature (28,-322,1960,-6769,13132,-13068,5040).

Formula

a(n) = 7*7^n + 3060*6^n + 93300*5^n + 893160*4^n + 4345560*3^n + 12867180*2^n + 22151340. - Christian Krause, Jun 14 2026

Example

Some solutions for 3X9
..0..4..0..6..0..6..1..6..2....0..6..0..5..0..5..3..2..0
..3..5..3..3..3..3..2..3..1....4..2..4..3..4..3..1..6..4
..0..4..0..6..0..6..1..6..2....0..6..0..5..0..5..3..2..0

Mathematica

A183671[n_] := 7*7^n + 3060*6^n + 93300*5^n + 893160*4^n + 4345560*3^n + 12867180*2^n + 22151340;
Array[A183671, 25] (* Paolo Xausa, Jun 15 2026 *)

Crossrefs

Column 8 of A183672.

Sequence in context: A164725 A164726 A237157 * A237339 A224589 A224590

Adjacent sequences: A183668 A183669 A183670 * A183672 A183673 A183674

Keyword

nonn,easy

Author

R. H. Hardin, Jan 06 2011

Extensions

a(6)-a(18) from Christian Krause, Jun 14 2026

Status

approved