A359809 Decimal expansion of the positive solution to tanh(x) = x/2.

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

Offset: 1

Author

M. F. Hasler, Jan 13 2023

Keywords

• nonn
• cons

Comments

Also, point where e^-(x/2 - 1)^2 + e^-(x/2 + 1)^2 has its maximum.

Examples

			1.91500804815453748135300306100481565...
		

Crossrefs

Cf. A309211.

Programs

Mathematica

RealDigits[x /. FindRoot[Tanh[x] == x/2, {x, 2}, WorkingPrecision -> 110], 10, 105][[1]] (* Amiram Eldar, Jan 13 2023 *)

PARI

localprec(199); digits(solve(x=1,2,tanh(x)-x/2)\.1^150)