A327600 a(n) is the largest k such that the sum of k consecutive reciprocals 1/p_n + ... + 1/p_(n+k-1) does not exceed 1 (where p_n = n-th prime).

2, 8, 26, 65, 143, 252, 423, 650, 976, 1391, 1865, 2478, 3168, 3980, 4977, 6136, 7419, 8828, 10476, 12278, 14294, 16612, 19123, 21905, 24903, 28055, 31493, 35319, 39485, 44101, 49115, 54102, 59467, 65142, 71314, 77648, 84503, 91719, 99302, 107364

Offset

1,1

Comments

The sequence is nondecreasing, since 1/p_n + ... + 1/p_(n+k-1) > 1/p_(n+1) + ... + 1/p_(n+k).

Links

Table of n, a(n) for n=1..40.

Formula

a(n) = A137368(n) - 1.

Example

For n = 1, since 1/p_1 + 1/p_2 = 1/2 + 1/3 = 5/6 <= 1 while 1/p_1 + 1/p_2 + 1/p_3 = 1/2 + 1/3 + 1/5 = 31/30 > 1, a(1) = 2.

Crossrefs

Analog of A136617. Cf. A137368.

Sequence in context: A227015 A216929 A100504 * A099416 A211885 A101696

Adjacent sequences: A327597 A327598 A327599 * A327601 A327602 A327603

Keyword

nonn

Author

Leon Bykov, Sep 18 2019

Status

approved