A064600 a(n) indicates the position of 5 after n iterations of A064553.

5, 7, 13, 37, 151, 863, 6689, 67139, 843377, 12903181

Offset

0,1

Comments

Iterating A064553 spreads the primes further and further apart, although 2 and 3 are fixed. For k < a(n) the n-th iteration of A064553 equals A003586.

Links

Table of n, a(n) for n=0..9.

Sean A. Irvine, Java program (github)

Formula

a(0) = 5 and a(n) = A000040(a(n - 1) - 1) for n > 0.

Example

a(3) = 37 as A064553(A064553(A064553(37))) = A064553(A064553(13)) = A064553(7) = 5.

Crossrefs

Cf. A064558, A000040, A064553, A003586, A064557, A064601.

Sequence in context: A018464 A063446 A339775 * A174874 A109904 A077781

Adjacent sequences: A064597 A064598 A064599 * A064601 A064602 A064603

Keyword

more,nonn

Author

Reinhard Zumkeller, Sep 22 2001

Extensions

a(9) from Sean A. Irvine, Jul 18 2023

Status

approved