A327701 Maximum value for base-n variant of A326344.

1, 20, 3, 107, 5, 310, 7, 668, 909, 1253, 11, 2082, 13, 3224, 3880, 4670, 17, 6558, 19

Offset

2,2

Comments

For each n >= 2, let b_n(k) be the base-n A326344-like sequence defined as follows:

- b_n(1) = 1;

- b_n(k) = R_n(nextprime(b_n(k - 1))) if k is prime;

- b_n(k) = R_n(nextcompo(b_n(k - 1))) if k is composite,

where R_n(x) writes x in reverse in base n, then converts back to decimal.

a(n) is the maximum value of b_n(k) for k >= 1. All listed terms so far have been established by automating the methods of Rémy Sigrist and Andrew Weimholt in A326344.

The obvious conjecture is that a(n) = n-1 iff n-1 is 1 or an odd prime. - N. J. A. Sloane, Oct 02 2019

Links

Table of n, a(n) for n=2..20.

Example

A326344 has a maximum value of 909, so a(10) = 909. A327241 has a maximum value of 310, so a(7) = 310.

Crossrefs

Cf. A326344, A326894, A327241.

Sequence in context: A248136 A040392 A317320 * A337157 A040388 A018816

Adjacent sequences: A327698 A327699 A327700 * A327702 A327703 A327704

Keyword

nonn,base,more

Author

Robert Dougherty-Bliss, Sep 29 2019.

Status

approved