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Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MolecularTopologicalIndex.html">Molecular Topological Index</a>.
From Amiram Eldar, Apr 16 2022: (Start)
Sum_{n>=2} 1/a(n) = 13/128 - Pi^2/64 + zeta(3)/16.
Sum_{n>=2} (-1)^n/a(n) = log(2)/4 - Pi^2/128 - 17/128 + 3*zeta(3)/64. (End)
(MAGMAMagma) [8*n*(n+1)*(n-1)^3: n in [1..30]]; // G. C. Greubel, Jan 04 2019
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[8*n*(n+1)*(n-1)^3$n=1..30]; # Muniru A Asiru, Jan 05 2019
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Molecular topological indices of the square graphs.
G. C. Greubel, <a href="/A192839/b192839.txt">Table of n, a(n) for n = 1..1000</a>
a(n) = 8*(-1+n)^3*(n*(+1+)*(n-1)^3.
G.f.: 48*x^2*(1+x)*(1+9*x)/(1-x)^6. [_- _Colin Barker_, Aug 07 2012]
E.g.f.: 8*x^2*(3 + 13*x + 8*x^2 + x^3)*exp(x). - G. C. Greubel, Jan 04 2019
Table[, {n, 1, 30}] (* G. C. Greubel, Jan 04 2019 *)
(PARI) vector(30, n, 8*n*(n+1)*(n-1)^3) \\ G. C. Greubel, Jan 04 2019
(MAGMA) [8*n*(n+1)*(n-1)^3: n in [1..30]]; // G. C. Greubel, Jan 04 2019
(Sage) [8*n*(n+1)*(n-1)^3 for n in (1..30)] # G. C. Greubel, Jan 04 2019
(GAP) List([1..30], n -> 8*n*(n+1)*(n-1)^3); # G. C. Greubel, Jan 04 2019
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