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 A122153 Decimal expansion of Parity Prime Constant: Sum_{k>=1} (-1)^(k+1) * 1/(2^prime(k)). 4

%I

%S 1,4,8,8,0,9,5,5,0,7,8,8,7,7,6,2,2,4,9,6,9,5,6,8,4,6,7,8,6,6,7,9,6,5,

%T 3,1,9,8,2,2,2,4,1,3,2,8,0,8,2,1,7,0,6,7,3,7,1,7,7,0,0,0,0,5,6,3,3,1,

%U 3,9,1,2,6,2,2,3,3,3,7,4,5,1,8,4,9,4,5,1,4,3,7,7,8,8,8,0,8,5,2

%N Decimal expansion of Parity Prime Constant: Sum_{k>=1} (-1)^(k+1) * 1/(2^prime(k)).

%C Binary expansion is given in A071986(n) = pi(n) mod 2.

%F Equals Sum_{k>=1} (-1)^(k+1) * 1/(2^prime(k)).

%F Equals lim_{n->infinity} A122150(n)/A034765(n).

%e 0.148809550788776224969568467866796531982224132808217067371770000563313912...

%t RealDigits[Sum[(-1)^(k+1)*1/2^Prime[k],{k,1,1000}],10,100]

%o (PARI) suminf(k=1, (-1)^(k+1) * 1/2^prime(k)) \\ _Michel Marcus_, Mar 20 2019

%Y Cf. A034765, A122150, A122151, A122152, A122153, A071986, A000720.

%K nonn,cons

%O 0,2

%A _Alexander Adamchuk_, Aug 22 2006

%E Offset corrected by _R. J. Mathar_, Feb 05 2009

%E Edited by _Michel Marcus_, Mar 20 2019

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Last modified October 16 20:35 EDT 2019. Contains 328103 sequences. (Running on oeis4.)