A182795 Number of n-colorings of the 10 X 10 X 10 triangular grid.

0, 0, 0, 6, 6468240187392, 143635721907943000938060, 4861091521972177266672058368000, 2856800670438221106476061284736341250, 131028911804088893672445293407292154494976

Offset: 0

Author

Alois P. Heinz, Dec 02 2010

Keywords

• nonn
• easy

Comments

The 10 X 10 X 10 triangular grid has 10 rows with k vertices in row k. Each vertex is connected to the neighbors in the same row and up to two vertices in each of the neighboring rows. The graph has 55 vertices and 135 edges altogether.

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..1000
• Wikipedia, Chromatic polynomial
• Wikipedia, Triangular grid graph
• Index entries for linear recurrences with constant coefficients, signature (56, -1540, 27720, -367290, 3819816, -32468436, 231917400, -1420494075, 7575968400, -35607051480, 148902215280, -558383307300, 1889912732400, -5804731963800, 16253249498640, -41648951840265, 97997533741800, -212327989773900, 424655979547800, -785613562163430, 1346766106565880, -2142582442263900, 3167295784216200, -4355031703297275, 5574440580220512, -6646448384109072, 7384942649010080, -7648690600760440, 7384942649010080, -6646448384109072, 5574440580220512, -4355031703297275, 3167295784216200, -2142582442263900, 1346766106565880, -785613562163430, 424655979547800, -212327989773900, 97997533741800, -41648951840265, 16253249498640, -5804731963800, 1889912732400, -558383307300, 148902215280, -35607051480, 7575968400, -1420494075, 231917400, -32468436, 3819816, -367290, 27720, -1540, 56, -1).

Crossrefs

10th column of A182797. Cf. A178435, A182798, A182788, A182789, A182790, A182791, A182792, A182793, A182794, A182796.

Programs

Maple

a:= n-> n^55 -135*n^54 +8964*n^53 -390222*n^52 [phone]*n^51 -316076903*n^50 [phone]*n^49 -113573987769*n^48 [phone]*n^47 -22113112510550*n^46 [phone]*n^45 -2609511250718613*n^44 +24045856082285419*n^43 -200371113856491240*n^42 +1518133675627952270*n^41 -10506651071221868153*n^40 +66680463251797921915*n^39 -389373183471975572302*n^38 +2098028797385404193010*n^37
-10456871082871436486097*n^36 +48311408769374448761586*n^35 -207268123118278617037243*n^34 +827002152243388922174239*n^33 -3072694198727638003487979*n^32 +10641864949286796056022377*n^31 -34383949683339954923684782*n^30 +103704885062207595279156312*n^29 -292098504456226533053440510*n^28 +768501708532085822533190556*n^27 -1888698433570434475839725929*n^26 +4335279422341414825800378209*n^25
-9290907905051445440799000716*n^24 +18580084162229028469273798451*n^23 -34646102938311786771803477712*n^22 +60179271229381177090538625964*n^21 -97248893234106206859587981511*n^20 +145984266730291101055714541723*n^19 -203195282517216004808829603690*n^18 +261670683045031491886557091942*n^17 -310956138275834795608083550274*n^16 +339941943100528554861813262560*n^15
-340628682378318048979653175381*n^14 +311484260127833509262781795600*n^13 -258586709722348835998646850788*n^12 +193670730551369756737363762352*n^11 -129863868693889627423240097464*n^10 +77228998619164716149657770512*n^9 -40252487790410927197535447840*n^8 +18109784947870880558334595968*n^7 -6892748007729626216676319168*n^6 +2158618972888431826460898944*n^5 -534180587663008964293559296*n^4
+97953970795833012084624384*n^3 -11833494445627750018634752*n^2 +706434229524151535286272*n: seq(a(n), n=0..12);

Formula

a(n) = n^55 -135*n^54 + ... (see Maple program).