A323828 Decimal expansion of a constant related to Bertrand's Postulate.

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

Offset: 1

Author

N. J. A. Sloane, Feb 01 2019

Keywords

• nonn
• cons

Examples

			3.5679760909846634612366007737192526425527943028977913311170116688989193092...
		

Links

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

Crossrefs

Cf. A249720, A051254.

Programs

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

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

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

Extensions

More terms from Freddy Barrera, Feb 17 2019