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A371941
Decimal expansion of Sum_{k>=0} (k+1)! / (2*k+1)!.
1
1, 3, 8, 8, 4, 4, 4, 8, 0, 4, 7, 0, 3, 9, 8, 9, 8, 6, 3, 4, 9, 0, 6, 2, 2, 5, 8, 1, 8, 0, 8, 5, 9, 4, 0, 3, 0, 9, 2, 6, 9, 2, 4, 9, 1, 8, 3, 2, 5, 4, 8, 0, 6, 5, 5, 6, 6, 3, 5, 2, 8, 7, 5, 4, 7, 9, 8, 0, 5, 5, 1, 9, 4, 2, 4, 9, 7, 6, 1, 3, 3, 5, 5, 4, 0, 8
OFFSET
1,2
FORMULA
Equals (1/4)*(2 + e^(1/4)*sqrt(Pi)*erf(1/2)).
Equals A248675/2. - Hugo Pfoertner, Apr 29 2024
EXAMPLE
1.38844480470398986349062258180859403...
MAPLE
hypergeom([2], [3/2], 1/4) ; evalf(%) ; # R. J. Mathar, Jul 03 2024
MATHEMATICA
s = Sum[(k + 1)!/(2 k+1)!, {k, 0, Infinity}]
d = N[s, 100]
First[RealDigits[d]]
CROSSREFS
Sequence in context: A019744 A252876 A102639 * A232182 A118817 A179553
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Apr 28 2024
STATUS
approved