A087636 Number of n-digit lunar primes.

0, 18, 81, 1539, 20457, 242217, 2894799, 33535839, 381591711

Offset: 1

Author

Marc LeBrun and N. J. A. Sloane, Oct 26 2003

Keywords

• nonn
• base
• more

Comments

Although a(1) through a(6) are divisible by 9, a(7) is not.

Links

• D. Applegate, C program for lunar arithmetic and number theory
• D. Applegate, M. LeBrun and N. J. A. Sloane, Dismal Arithmetic, arxiv:1107.1130 [math.NT], July 2011. [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]
• D. Applegate, M. LeBrun, and N. J. A. Sloane, Dismal Arithmetic, J. Int. Seq. 14 (2011) # 11.9.8.
• Benjamin Baily, Justine Dell, Henry L. Fleischmann, Faye Jackson, Steven J. Miller, Ethan Pesikoff, and Luke Reifenberg, Irreducibility over the max-min semiring, arXiv:2111.09786 [math.CO], 2021.
• Index entries for sequences related to dismal (or lunar) arithmetic

Crossrefs

Cf. A087062 (lunar product), A087097 (lunar primes), A087638 (partial sums).

Programs

PARI

A87636=[]; A087636(n)={while(#A87636A087097(k)); A87636[n]} \\ Store results in array A87636 to avoid re-calculation. - M. F. Hasler, Nov 15 2018

Extensions

a(6)-a(9) from David Applegate, Nov 07 2003