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A332628
Decimal expansion of arclength between inflection points of standard normal density function.
0
2, 0, 2, 9, 8, 2, 8, 1, 8, 1, 4, 3, 9, 2, 2, 6, 9, 6, 7, 1, 0, 3, 3, 3, 0, 5, 1, 6, 2, 6, 6, 9, 1, 6, 6, 3, 4, 0, 9, 4, 0, 1, 2, 6, 9, 9, 5, 6, 9, 8, 4, 2, 6, 4, 6, 2, 6, 7, 2, 2, 9, 4, 7, 1, 8, 4, 3, 1, 7, 1, 0, 2, 7, 9, 9, 3, 0, 7, 7, 8, 6, 2, 8, 4, 0, 8
OFFSET
1,1
COMMENTS
The inflection points are (-1,1) and (1,1), corresponding to one standard deviation.
EXAMPLE
arclength = 2.02982818143922696710333051626691663409401269956...
MATHEMATICA
s = Integrate[Sqrt[1 + (E^-x^2 x^2)/(2 Pi)], {x, -1, 1}]
r = N[s, 200]
RealDigits[r][[1]]
PROG
(PARI) intnum(x=-1, 1, sqrt(1+exp(-x^2)*x^2/(2*Pi))) \\ Michel Marcus, May 13 2020
CROSSREFS
Cf. A333205.
Sequence in context: A137302 A324305 A265607 * A091518 A096734 A220234
KEYWORD
nonn,cons,easy
AUTHOR
Clark Kimberling, May 13 2020
STATUS
approved