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

0,1

References

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

Links

Table of n, a(n) for n=0..18.

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

Formula

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

Crossrefs

Cf. A138288. Equals 2*A054320.

Sequence in context: A308313 A304024 A239688 * A336894 A037567 A174200

Adjacent sequences: A350962 A350963 A350964 * A350966 A350967 A350968

Keyword

nonn,easy

Author

N. J. A. Sloane, Mar 02 2022

Status

approved