OFFSET
1,2
COMMENTS
This constant is irrational (Stucky, 2016). - Amiram Eldar, Apr 30 2023
LINKS
Joshua Stucky, Several Theorems Concerning the Irrationality of Certain Infinite Series Involving Tetrations, The Pentagon, Vol. 75, No. 2 (2016), pp. 4-9.
Eric Weisstein's World of Mathematics, Hyperfactorial.
EXAMPLE
1.2592954398150628876913596498837350926311457518421...
MATHEMATICA
With[{m = 105}, RealDigits[N[Sum[1/Hyperfactorial[n], {n, 1, Infinity}], m + 2], 10, m][[1]]] (* Amiram Eldar, Apr 30 2023 *)
RealDigits[Total[Table[1/Times@@(Range[n]^Range[n]), {n, 30}]], 10, 120][[1]] (* Harvey P. Dale, Oct 07 2023 *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Ilya Gutkovskiy, Aug 28 2021
STATUS
approved