A068239 1/2 the number of colorings of a 3 X 3 square array with n colors.

1, 123, 4806, 71410, 583455, 3232341, 13675228, 47502036, 141991245, 377162335, 910842306, 2033854758, 4253012491, 8411348505, 15856955640, 28673921896, 49991146713, 84387303171, 138412872190, 221253017370, 345558093111, 528471784093, 792890261076

Offset

2,2

Links

Alois P. Heinz, Table of n, a(n) for n = 2..1000

Formula

From Alois P. Heinz, Apr 27 2012: (Start)

G.f.: x^2*(1199*x^7 +16567*x^6 +60099*x^5 +71075*x^4 +28765*x^3 +3621*x^2 +113*x+1) / (x-1)^10.

a(n) = (79*n -323*n^2 +594*n^3 -648*n^4 +459*n^5 -216*n^6 +66*n^7 -12*n^8 +n^9) / 2.

(End)

Maple

a:= n-> (79+(-323+(594+(-648+(459+(-216+(66+(-12+n)*n)*n) *n)*n)*n)*n)*n) *n/2:
seq(a(n), n=2..30); # Alois P. Heinz, Apr 27 2012

Crossrefs

Cf. A068239-A068305, A000332, A002417, A027441, A182368, A182406.

Sequence in context: A163711 A293309 A297754 * A098683 A324435 A135479

Adjacent sequences: A068236 A068237 A068238 * A068240 A068241 A068242

Keyword

nonn

Author

R. H. Hardin, Feb 24 2002

Status

approved