A334183 Number of dimer tilings of a 2*n x 14 Moebius strip.
1, 843, 2226851, 7009284232, 23313951730593, 79684937704014787, 276820366633357961907, 971684488369988888850993, 3433809783046699326165318697, 12187832583695135440208385490411, 43381711462091769247169214041784216, 154696550169813236996441805153918153313
Offset: 0
Keywords
Programs
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Mathematica
a[n_] := 2^n * Sqrt[Resultant[ChebyshevU[2*n, x/2], ChebyshevT[14, I*x/2], x]]; Array[a, 12, 0] (* Amiram Eldar, May 04 2021 *)
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PARI
{a(n) = sqrtint(4^n*polresultant(polchebyshev(2*n, 2, x/2), polchebyshev(14, 1, I*x/2)))}
Formula
a(n)^2 = 4^n * Resultant(U_{2*n}(x/2), T_{14}(i*x/2)), where T_n(x) is a Chebyshev polynomial of the first kind, U_n(x) is a Chebyshev polynomial of the second kind and i = sqrt(-1).