A308751 a(n) = (2 + Sum_{k = 1..n-1} A095258(k)) / A095258(n).

2, 1, 3, 2, 2, 2, 1, 3, 9, 16, 5, 3, 2, 17, 9, 24, 10, 25, 22, 13, 46, 7, 4, 2, 47, 45, 23, 16, 16, 3, 2, 17, 51, 72, 26, 9, 73, 111, 160, 49, 46, 5, 47, 72, 20, 146, 63, 112, 28, 113, 174, 95, 80, 63, 54, 160, 46, 11, 47, 72, 14, 12, 73, 130, 37, 131, 152, 51

Offset: 1

Author

Rémy Sigrist, Jun 22 2019

Keywords

• nonn
• look

Comments

Are there infinitely many 1's in this sequence?

Examples

			a(3) = (2 + A095258(1) + A095258(2)) / A095258(3) = (2 + 1 + 3) / 2 = 3.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, PARI program for A308751

Crossrefs

Cf. A095258.

Programs

PARI

See Links section.

Python

from itertools import islice
from sympy import divisors
def A308751_gen(): # generator of terms
    bset, s = {1}, 3
    yield 2
    while True:
        for d in divisors(s):
            if d not in bset:
                yield s//d
                bset.add(d)
                s += d
                break
A308751_list = list(islice(A308751_gen(),30)) # Chai Wah Wu, Jan 25 2022