A238261 Decimal expansion of a constant related to A187235.

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

Offset

1,1

Links

Table of n, a(n) for n=1..105.

V. Kotesovec, Non-attacking chess pieces, 6ed, 2013, p.261.

Formula

Equals lim n->infinity (A187235(n)/(n-1)!)^(1/n).

Equals -(2*LambertW(-1,-exp(-1/2)/2))^2 / (1 + 2*LambertW(-1,-exp(-1/2)/2)).

Example

4.9108149645682558987515348...

Mathematica

RealDigits[N[-(2*LambertW[-1, -1/2/Sqrt[E]])^2/(1+2*LambertW[-1, -1/2/Sqrt[E]]), 105]][[1]]

Crossrefs

Cf. A187235, A238262, A002465, A129256, A342111, A330287.

Sequence in context: A334657 A364241 A011514 * A245238 A011238 A002993

Adjacent sequences: A238258 A238259 A238260 * A238262 A238263 A238264

Keyword

nonn,cons

Author

Vaclav Kotesovec, Feb 21 2014

Status

approved