A157991 Number of n-colorings of the Levi Graph.

0, 0, 2, 5514234, 2883040542828, 40804091270010980, 60520556880158419470, 21901769993996949991662, 3041658168762971457654584, 211558602330274827202235208, 8728129703136293355833601210, 239394223814453881755898003490, 4731013227415233819791988908772

Offset

0,3

Comments

The Levi Graph has 30 nodes and 45 edges.

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Timme, Marc; van Bussel, Frank; Fliegner, Denny; Stolzenberg, Sebastian (2009) "Counting complex disordered states by efficient pattern matching: chromatic polynomials and Potts partition functions", New J. Phys. 11 023001, doi: 10.1088/1367-2630/11/2/023001.

Weisstein, Eric W. "Levi Graph".

Weisstein, Eric W. "Chromatic Polynomial".

Index entries for linear recurrences with constant coefficients, signature (31, -465, 4495, -31465, 169911, -736281, 2629575, -7888725, 20160075, -44352165, 84672315, -141120525, 206253075, -265182525, 300540195, -300540195, 265182525, -206253075, 141120525, -84672315, 44352165, -20160075, 7888725, -2629575, 736281, -169911, 31465, -4495, 465, -31, 1).

Formula

a(n) = n^30 -45*n^29 + ... (see Maple program).

Maple

a:= n-> n^30 -45*n^29 +990*n^28 -14190*n^27 +148995*n^26 -1221759*n^25 +8145060*n^24 -45379530*n^23 +215549775*n^22 -886099793*n^21 +3189425574*n^20 -10143911580*n^19 +28714411485*n^18 -72754429695*n^17 +165716335841*n^16 -340379666835*n^15 +631649660595*n^14 -1059695941005*n^13 +1606062587021*n^12 -2193946401123*n^11 +2690139367971*n^10 -2941870019235*n^9 +2842645627185*n^8 -2395149923590*n^7 +1727156333706*n^6 -1037572912125*n^5 +498710054365*n^4 -179700698265*n^3 +43072277935*n^2 -5133307729*n:
seq(a(n), n=0..30);

Crossrefs

Sequence in context: A158347 A273354 A352126 * A233555 A273729 A324440

Adjacent sequences: A157988 A157989 A157990 * A157992 A157993 A157994

Keyword

nonn,easy

Author

Alois P. Heinz, Mar 10 2009

Status

approved