A135004 Decimal expansion of 4/e.

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

Offset: 1

Author

Omar E. Pol, Nov 15 2007

Keywords

• cons
• nonn

Comments

Leading coefficient of energy difference between the two lowest states of the hydrogen molecular ion (see Holstein-Herring Method link). - Andrea Pinos, Nov 22 2023

Examples

			1.471517764685769...
		

Links

• G. C. Greubel, Table of n, a(n) for n = 1..2000
• Shawn Godin, Problem CC35, Crux Mathematicorum, Vol. 38, No. 7 (2012), p. 265; Solution to Problem CC35, ibid., Vol. 39, No. 7 (2013), p. 299.
• Wikipedia, Holstein-Herring Method.

Crossrefs

Cf. A019741 (e/4), A068985 (1/e), A135002 (2/e).

Programs

Maple

Digits:=100: evalf(4/exp(1)); # Wesley Ivan Hurt, Jan 19 2017

Mathematica

RealDigits[4/E,10,120][[1]] (* Harvey P. Dale, Mar 06 2012 *)

PARI

4/exp(1) \\ Michel Marcus, Jan 20 2017

Formula

Equals lim_{n->oo} (((2*n)!/n!)^(1/n))/n (Godin, 2012). - Amiram Eldar, Apr 02 2022

Extensions

More terms from Harvey P. Dale, Mar 06 2012