A183663 Number of (n+1) X (n+1) 0..6 arrays with every 2 X 2 subblock summing to 12.

231, 5215, 100935, 1803007, 30722151, 508151455, 8242978695, 131986793407, 2094954565671, 33056843072095, 519574783811655, 8145788707438207, 127508337241609191, 1994179177513903135, 31176263724084823815, 487384513498854809407, 7621092558027755148711, 119217319608827297348575

Offset

1,1

Links

Paolo Xausa, Table of n, a(n) for n = 1..800

Christian Krause, Proof of formula, Jun 19 2026

Index entries for linear recurrences with constant coefficients, signature (88,-3382,74500,-1036669,9450292,-56441868,212981040,-460771200,435456000).

Formula

a(n) = 16*16^n + 30*15^n - 24*12^n - 40*10^n + 9*9^n + 16*8^n + 14*7^n - 24*6^n + 10*5^n. - Christian Krause, Jun 19 2026

Example

Some solutions for 3 X 3:
..6..4..6....0..5..0....4..1..4....0..4..0....5..1..5....2..3..2....4..4..3
..1..1..1....3..4..3....3..4..3....5..3..5....4..2..4....1..6..1....0..4..1
..6..4..6....3..2..3....3..2..3....0..4..0....1..5..1....4..1..4....5..3..4

Mathematica

A183663[n_] := 16*16^n + 30*15^n - 24*12^n - 40*10^n + 9*9^n + 16*8^n + 14*7^n - 24*6^n + 10*5^n;
Array[A183663, 25] (* Paolo Xausa, Jun 22 2026 *)

Crossrefs

Main diagonal of A183672.

Sequence in context: A211717 A029569 A152102 * A362429 A201957 A152500

Adjacent sequences: A183660 A183661 A183662 * A183664 A183665 A183666

Keyword

nonn,easy,changed

Author

R. H. Hardin, Jan 06 2011

Extensions

a(6)-a(18) from Christian Krause, Jun 19 2026

Status

approved