A364824 Index of prime(n) in A067836, or -1 if prime(n) does not occur in it.

1, 2, 3, 4, 6, 5, 7, 8, 9, 12, 13, 10, 19, 14, 20, 16, 26, 42, 18, 25, 11, 15, 17, 43, 118, 33, 24, 31, 29, 212, 40, 68, 30, 98, 22, 45, 34, 109, 28, 39, 21, 23, 46, 143, 27, 35, 37, 55, 47, 123, 58, 90, 132, 32, 139, 91, 41, 44, 38, 52, 36, 77, 54, 48, 53, 83, 51

Offset

1,2

Comments

All terms in A067836 are distinct, making this sequence defined.

If the conjecture holds that A067836 contains only primes, then a(A062894(n)) = n.

If all primes eventually occur in A067836, then all terms in this sequence are positive and A062894(a(n)) = n.

Links

Table of n, a(n) for n=1..67.

Prog

(Python)
from itertools import count
from sympy import prime, nextprime
def A364824(n):
    a, f, p = 2, 1, prime(n)
    for i in count(1):
        if a == p:
            return i
        a=nextprime((f:=f*a)+1)-f # Chai Wah Wu, Sep 09 2023

Crossrefs

Cf. A062894, A067836.

Sequence in context: A121730 A275659 A244321 * A062894 A339723 A129606

Adjacent sequences: A364821 A364822 A364823 * A364825 A364826 A364827

Keyword

nonn

Author

Bert Dobbelaere, Aug 09 2023

Status

approved