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A323828 Decimal expansion of a constant related to Bertrand's Postulate. 0
3, 5, 6, 7, 9, 7, 6, 0, 9, 0, 9, 8, 4, 6, 6, 3, 4, 6, 1, 2, 3, 6, 6, 0, 0, 7, 7, 3, 7, 1, 9, 2, 5, 2, 6, 4, 2, 5, 5, 2, 7, 9, 4, 3, 0, 2, 8, 9, 7, 7, 9, 1, 3, 3, 1, 1, 1, 7, 0, 1, 1, 6, 6, 8, 8, 9, 8, 9, 1, 9, 3, 0, 9, 2, 0, 0, 5, 1, 4, 6, 0, 2, 5, 8, 3, 4, 2, 9, 4, 0, 7, 4, 1, 6, 0, 4, 9, 4, 7, 7, 7, 5 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..102.

Dylan Fridman et al., A prime-representing constant, Amer. Math. Monthly 126 (2019), 72-73 (on ResearchGate).

FORMULA

Sum_{k>=1} (2^(k-1) + 1)/(Product_{i=1..k-1} 2^(i-1) + 2). See Dylan Fridman et al. reference. - Freddy Barrera, Feb 17 2019

EXAMPLE

3.5679760909846634612366007737192526425527943028977913311170116688989193092...

MAPLE

evalf(Sum((2^(k-1) + 1)/Product(2^(i-1) + 2, i=1..k-1), k=1..infinity), 120); # Vaclav Kotesovec, Jun 04 2019

PROG

(Sage)

def g(n):

    return sum((2^(k-1) + 1)/prod(2^(i-1) + 2 for i in (1..k-1))

               for k in (1..n))

N(g(100), digits=102) # Freddy Barrera, Feb 17 2019

CROSSREFS

Cf. A249720, A051254.

Sequence in context: A010906 A114309 A324060 * A079581 A229858 A269020

Adjacent sequences:  A323825 A323826 A323827 * A323829 A323830 A323831

KEYWORD

nonn,cons

AUTHOR

N. J. A. Sloane, Feb 01 2019

EXTENSIONS

More terms from Freddy Barrera, Feb 17 2019

STATUS

approved

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Last modified February 27 06:03 EST 2020. Contains 332299 sequences. (Running on oeis4.)