cp's OEIS Frontend

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

%I A323828 #20 Jun 04 2019 03:02:44
%S A323828 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,
%T A323828 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,
%U A323828 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
%N A323828 Decimal expansion of a constant related to Bertrand's Postulate.
%H A323828 Dylan Fridman et al., <a href="https://www.researchgate.net/publication/330746181_A_Prime-Representing_Constant">A prime-representing constant</a>, Amer. Math. Monthly 126 (2019), 72-73 (on ResearchGate).
%F A323828 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
%e A323828 3.5679760909846634612366007737192526425527943028977913311170116688989193092...
%p A323828 evalf(Sum((2^(k-1) + 1)/Product(2^(i-1) + 2, i=1..k-1), k=1..infinity), 120); # _Vaclav Kotesovec_, Jun 04 2019
%o A323828 (Sage)
%o A323828 def g(n):
%o A323828     return sum((2^(k-1) + 1)/prod(2^(i-1) + 2 for i in (1..k-1))
%o A323828                for k in (1..n))
%o A323828 N(g(100), digits=102) # _Freddy Barrera_, Feb 17 2019
%Y A323828 Cf. A249720, A051254.
%K A323828 nonn,cons
%O A323828 1,1
%A A323828 _N. J. A. Sloane_, Feb 01 2019
%E A323828 More terms from _Freddy Barrera_, Feb 17 2019