%I #13 May 03 2012 07:16:12
%S 1,672384,24673292910,47694893373440,16222878355401375,
%T 1842996126472816896,98798500424990038764,3068393771393664491520,
%U 62960689342002146953005,933100311834971308336000,10639781338324232990590266,97779035968707368095801344,750090455889142956720814955
%N 1/6 the number of colorings of a 5 X 5 rhombic hexagonal array with n colors.
%H Alois P. Heinz, <a href="/A068246/b068246.txt">Table of n, a(n) for n = 3..1000</a>
%F 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
%p a:= n-> (3008737472+ (-26856982336+ (115567646848+ (-319382723824+ (636837385892+ (-975405045160+ (1192546680096+ (-1193738274422+ (995467197535+ (-699933854941+ (418375982241+ (-213720456031+ (93568827565+ (-35133626327+ (11298632622+
%p (-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:
%p seq (a(n), n=3..40); # _Alois P. Heinz_, May 02 2012
%Y Cf. A068239-A068305, A000332, A002417, A027441, A212162, A212163.
%K nonn
%O 3,2
%A _R. H. Hardin_, Feb 24 2002
%E Extended beyond a(10) by _Alois P. Heinz_, May 02 2012
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