A363842 Decimal expansion of Sum_{k>=0} 1/(k!)!^2.

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

Offset

1,1

Comments

1166401/518400 approximates this constant to 48 significant digits.

Links

Table of n, a(n) for n=1..87.

Example

2.25000192901234567901234567901234567901234567901...

Mathematica

RealDigits[Sum[1/(k!)!^2, {k, 0, 4}], 10, 100][[1]]

Prog

(PARI) suminf(k=0, 1/k!!^2)

Crossrefs

Cf. A363841 (continued fraction).

Cf. A336686.

Sequence in context: A264933 A012858 A366756 * A292383 A332896 A100247

Adjacent sequences: A363839 A363840 A363841 * A363843 A363844 A363845

Keyword

nonn,cons

Author

Daniel Hoyt, Jun 23 2023

Status

approved