A036344 Prime concatenated analog clock numbers (clockwise and counterclockwise).

2, 3, 5, 7, 11, 23, 43, 67, 89, 109, 4567, 10987, 76543, 23456789, 6543211211, 4321121110987, 23456789101112123, 891011121234567891011, 3211211109876543211211, 23456789101112123456789101112123, 43211211109876543211211109876543, 567891011121234567891011121234567891011

Offset: 1

Author

Patrick De Geest, Dec 15 1998

Keywords

• nonn
• base

Comments

The hours 10, 11 and 12 are taken 'complete and unreversed'.

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..40
• Carlos Rivera, Puzzle 19. Primes on a clock, The Prime Puzzles & Problems Connection.
• Eric Weisstein's World of Mathematics, Clock Prime.

Crossrefs

Cf. A034326, A036342, A036343.

Formula

Union of A036342 and A036343. - Sean A. Irvine, Oct 26 2020

Extensions

Offset corrected and a(21) from Sean A. Irvine, Oct 26 2020

a(22) and beyond from Michael S. Branicky, May 20 2024