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
EXAMPLE
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Robert Dougherty-Bliss, Sep 29 2019.
STATUS
approved