A376068 Lexicographically earliest sequence of distinct positive integers such that for any n > 0, Sum_{k = 1..n} a(2*k-1)/a(2*k) < 1.

1, 2, 3, 7, 4, 57, 5, 3991, 6, 19108909, 8, 486867178748497, 9, 266669605960335497200501136827, 10, 79014087492267334815685283447201270968760518233020971656781, 11

Offset

1,2

Comments

This sequence is a permutation of the positive integers.

Links

Table of n, a(n) for n=1..17.

Rémy Sigrist, PARI program

Index entries for sequences that are permutations of the natural numbers

Example

The first terms, alongside the corresponding sums, are:
  n  a(2*n-1)  a(2*n)    Sum_{k=1..n} a(2*k-1)/a(2*k)
  -  --------  --------  -----------------------------
  1         1         2  1/2
  2         3         7  13/14
  3         4        57  797/798
  4         5      3991  3184817/3184818
  5         6  19108909  60858397343561/60858397343562

Prog

(PARI) \\ See Links section.

Crossrefs

Cf. A376043.

Sequence in context: A324598 A229794 A331318 * A082734 A332526 A021425

Adjacent sequences: A376065 A376066 A376067 * A376069 A376070 A376071

Keyword

nonn

Author

Rémy Sigrist, Sep 08 2024

Status

approved