A068246 1/6 the number of colorings of a 5 X 5 rhombic hexagonal array with n colors.

1, 672384, 24673292910, 47694893373440, 16222878355401375, 1842996126472816896, 98798500424990038764, 3068393771393664491520, 62960689342002146953005, 933100311834971308336000, 10639781338324232990590266, 97779035968707368095801344, 750090455889142956720814955

Offset

3,2

Links

Alois P. Heinz, Table of n, a(n) for n = 3..1000

Formula

G.f.: (1155805517421*x^22 +898154715023598*x^21 +153334491715682431*x^20 +9260621966248364140*x^19 +250086793798293779695*x^18 +3463005755473293705486*x^17 +26809839147864527991573*x^16 +122805799859998392511056*x^15 +345417237429621912129330*x^14 +610511151468783633149340*x^13 +686259871966584143669766*x^12 +491767778082675626596168*x^11 +223082415423639038320846*x^10 +62970879259692393145420*x^9 +10739574336476388551610*x^8 +1057138433525073018576*x^7 +56029398700931117553*x^6 +1436637989069258166*x^5 +14990828199704235*x^4 +47053606279980*x^3 +24655811251*x^2+672358*x+1)*x^3 / (x-1)^26. - Alois P. Heinz, May 02 2012

Maple

a:= n-> (3008737472+ (-26856982336+ (115567646848+ (-319382723824+ (636837385892+ (-975405045160+ (1192546680096+ (-1193738274422+ (995467197535+ (-699933854941+ (418375982241+ (-213720456031+ (93568827565+ (-35133626327+ (11298632622+
(-3101089711+ (722137763+ (-141421592+ (23000726+ (-3051871+ (321994+ (-25992+ (1508+(-56+n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n) *n/6:
seq (a(n), n=3..40); #  Alois P. Heinz, May 02 2012

Crossrefs

Cf. A068239-A068305, A000332, A002417, A027441, A212162, A212163.

Sequence in context: A251503 A084977 A049499 * A359499 A068248 A206324

Adjacent sequences: A068243 A068244 A068245 * A068247 A068248 A068249

Keyword

nonn

Author

R. H. Hardin, Feb 24 2002

Extensions

Extended beyond a(10) by Alois P. Heinz, May 02 2012

Status

approved