A350965 a(n) = sqrt(6*A138288(n)^2 - 2).

2, 22, 218, 2158, 21362, 211462, 2093258, 20721118, 205117922, 2030458102, 20099463098, 198964172878, 1969542265682, 19496458483942, 192995042573738, 1910453967253438, 18911544629960642, 187204992332352982, 1853138378693569178

Offset: 0

Author

N. J. A. Sloane, Mar 02 2022

Keywords

• nonn
• easy

References

• H. Brocard, Note #2049, L'Intermédiaire des Mathématiciens, 8 (1901), pp. 212-213.

Links

• Index entries for linear recurrences with constant coefficients, signature (10,-1).

Crossrefs

Cf. A138288. Equals 2*A054320.

Formula

G.f.: 2*(1+x)/(1-10*x+x^2) . - R. J. Mathar, Mar 07 2022