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A192832
Molecular topological indices of the lattice graphs.
1
0, 48, 576, 2880, 9600, 25200, 56448, 112896, 207360, 356400, 580800, 906048, 1362816, 1987440, 2822400, 3916800, 5326848, 7116336, 9357120, 12129600, 15523200, 19636848, 24579456, 30470400, 37440000, 45630000, 55194048, 66298176, 79121280, 93855600
OFFSET
1,2
COMMENTS
Lattice graphs are defined for n>=2; extended to n=1 using closed form.
LINKS
Eric Weisstein's World of Mathematics, Lattice Graph
Eric Weisstein's World of Mathematics, Molecular Topological Index
FORMULA
a(n) = 4*n^2*(n+1)*(n-1)^2.
a(n) = 48*A004302(n).
G.f.: 48*x^2*(1+6*x+3*x^2)/(1-x)^6. - Colin Barker, Aug 07 2012
E.g.f.: 4*x^2*(6 +18*x +9*x^2 +x^3)*exp(x). - G. C. Greubel, Jan 04 2019
MATHEMATICA
Table[4*n^2*(n+1)*(n-1)^2, {n, 1, 30}] (* G. C. Greubel, Jan 04 2019 *)
PROG
(PARI) vector(30, n, 4*n^2*(n+1)*(n-1)^2) \\ G. C. Greubel, Jan 04 2019
(Magma) [4*n^2*(n+1)*(n-1)^2: n in [1..30]]; // G. C. Greubel, Jan 04 2019
(Sage) [4*n^2*(n+1)*(n-1)^2 for n in (1..30)] # G. C. Greubel, Jan 04 2019
(GAP) List([0..30], n -> 4*n^2*(n+1)*(n-1)^2); # G. C. Greubel, Jan 04 2019
CROSSREFS
Sequence in context: A334713 A266210 A245953 * A352847 A042949 A190601
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Jul 11 2011
STATUS
approved