A192793 Molecular topological indices of the crossed prism graphs.

108, 360, 900, 1872, 3420, 5688, 8820, 12960, 18252, 24840, 32868, 42480, 53820, 67032, 82260, 99648, 119340, 141480, 166212, 193680, 224028, 257400, 293940, 333792, 377100, 424008, 474660, 529200, 587772, 650520, 717588, 789120, 865260, 946152, 1031940, 1122768

Offset: 1

Author

Eric W. Weisstein, Jul 10 2011

Keywords

• nonn
• easy
• changed

Links

• Eric Weisstein's World of Mathematics, Crossed Prism Graph.
• Eric Weisstein's World of Mathematics, Molecular Topological Index.
• Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Crossrefs

Cf. A047667.

Programs

PARI

my(x='x+O('x^37)); Vec(36*x*(3-2*x+3*x^2)/(x-1)^4) \\ Elmo R. Oliveira, Aug 26 2025

Formula

a(n) = 12*n*(2*n^2 + 7).

G.f.: 36*x*(3*x^2-2*x+3)/(x-1)^4. - Colin Barker, Nov 04 2012

From Elmo R. Oliveira, Aug 26 2025: (Start)

E.g.f.: 12*x*(9 + 6*x + 2*x^2)*exp(x).

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n > 4.

a(n) = 36*A047667(n). (End)

Extensions

More terms from Elmo R. Oliveira, Aug 26 2025