A390750 - OEIS

%I #11 May 19 2026 23:06:08

%S 4,0,9,3,5,5,5,7,7,1,3,8,6,6,2,2,8,6,3,2,1,6,1,0,2,8,0,5,7,2,1,1,5,1,

%T 5,4,0,0,8,0,5,1,3,2,9,9,3,3,7,9,5,3,9,1,8,4,5,2,6,7,7,7,8,5,5,7,6,1,

%U 5,4,3,7,7,9,6,6,8,2,6,4,0,2,8,8,8,1,9,8,0,6,8,5,8,0,6,8,7,9,6,8

%N Decimal expansion of 2 + sqrt(A058265) + 1/sqrt(A058265).

%H Zhaoxi Li, Jianfeng Wang, Shi-Mei Ma, and Francesco Belardo, <a href="https://doi.org/10.1017/S0013091525101247">Hoffman program of Laplacian matching polynomials of graphs</a>, Proceedings of the Edinburgh Mathematical Society, pp. 1-18 (2025).

%H <a href="/index/Al#algebraic_06">Index entries for algebraic numbers, degree 6</a>.

%F Minimal polynomial: x^6 - 12*x^5 + 54*x^4 - 112*x^3 + 104*x^2 - 32*x - 4.

%e 4.09355577138662286321610280572115154008051329933795391845267778557615437796....

%t A058265:=(CubeRoot[19+3Sqrt[33]]+CubeRoot[19-3Sqrt[33]]+1)/3; (* A058265 *)

%t RealDigits[2+Sqrt[A058265]+1/Sqrt[A058265], 10, 100][[1]]

%o (PARI) polrootsreal(x^6 - 12*x^5 + 54*x^4 - 112*x^3 + 104*x^2 - 32*x - 4)[2] \\ _Charles R Greathouse IV_, May 19 2026

%Y Cf. A058265.

%K nonn,cons,easy

%O 1,1

%A _Stefano Spezia_, Nov 17 2025