A156116 Five-digit mountain-type primes that increase to and decrease from the central digit, including palindromes.

12421, 12541, 12641, 12653, 12721, 12743, 12763, 12821, 12841, 12853, 12941, 12953, 12973, 12983, 13421, 13721, 13751, 13763, 13831, 13841, 13873, 13921, 13931, 13963, 14543, 14621, 14653, 14731, 14741, 14753, 14821, 14831, 14843, 14851, 14951, 14983

Offset: 1

Author

Ki Punches, Feb 14 2009

Keywords

• nonn
• base
• easy
• fini
• full

Comments

Sequence is finite, ending with a(185) = 78941.

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..185 (full sequence)

Programs

Maple

for a from 1 to 9 do for b from a+1 to 9 do for c from b+1 to 9 do for d from 2 to c-1 do for e from 1 to d-1 do n:=10000*a+1000*b+100*c+10*d+e: if(isprime(n))then printf("%d, ",n): fi: od:od:od:od:od: # Nathaniel Johnston, Jun 23 2011

Extensions

Minor edits by Ray Chandler, Feb 20 2009