OFFSET
1,2
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 1..1000
H. S. Uhler, On the numerical value of i^i, Amer. Math. Monthly, 28 (1921), 114-116.
EXAMPLE
1.6880917949644686006168476280967822941196811892871823125684056078889433931696...
MATHEMATICA
RealDigits[Exp[Pi/6], 10, 111][[1]] (* or *)
a[0] = a[1] = 1; a[n_] := ((n - 2)^2 + 1) a[n - 2]; t[x_] := N[(1/2)^x*a[x]/x!, 128]; RealDigits[Sum[t[x], {x, 0, 421}], 10, 111][[1]] (* Robert G. Wilson v, Feb 16 2019 *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
N. J. A. Sloane, Feb 11 2019
EXTENSIONS
Corrected and extended by Robert G. Wilson v, Feb 16 2019
STATUS
approved