A118849 Digital clock primes such that the number of minutes past midnight is also prime.

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 101, 107, 113, 137, 149, 211, 229, 311, 313, 317, 331, 347, 349, 353, 359, 401, 431, 443, 547, 607, 613, 619, 641, 659, 701, 719, 743, 811, 823, 829, 907, 929, 937, 947, 953, 1013, 1019, 1031, 1117

Offset: 1

Author

Carl R. White, May 01 2006

Keywords

• nonn
• base
• easy
• fini
• full

Comments

The number of minutes past midnight represented by each of the times here can be found in A118850.

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..83 (full sequence)

Crossrefs

Cf. A050246, A118848, A118850.

Programs

Maple

for h from 0 to 23 do for m from 0 to 59 do t:=100*h+m: if(isprime(60*h+m) and isprime(t))then printf("%d, ", t): fi: od: od: # Nathaniel Johnston, May 17 2011

Formula

a(n) = A118850(n) + floor(A118850(n)/60)*40.