A103592 a(n) is the smallest prime p such that Sum_{primes q <= p} 1/q >= n/2.

2, 5, 29, 277, 11789, 5195977, 118185163069, 1801241230056600523

Offset: 1

Author

James R. Buddenhagen, Mar 28 2005

Keywords

• nonn

Crossrefs

Cf. A016088, A046024, A103591-A103600.

Programs

Mathematica

Table[m = 1; s = 0; While[(s = s + 1/Prime[m]) < n/2, m++];
Prime[m], {n, 1, 8}] (* Robert Price, Mar 27 2019 *)

Extensions

a(7)-a(8) from Martin Raab, Aug 24 2008

a(7) corrected by Martin Raab, Mar 31 2009