

A105347


Concatenation of the largest and the smallest ndigit primes (in that order).


0



72, 9711, 997101, 99731009, 9999110007, 999983100003, 99999911000003, 9999998910000019, 999999937100000007, 99999999671000000007, 9999999997710000000019, 999999999989100000000003
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..12.
Chris Caldwell, The First 10,000 Primes.


EXAMPLE

The largest and smallest 1digit primes are 7 and 2, so the first term is 72.
The largest and smallest 2digit primes are 97 and 11, so the second term is 9711.


MAPLE

for n from 0 to 30 do for m from 1 to 10^(n+1)1 do if isprime(10^(n+1)  m) then printf(`%d`, 10^(n+1)m); break; fi: od: for m from 1 to 10^(n+1)1 do if isprime(10^n + m) then printf(`%d`, 10^n+m); break; fi: od: printf(`, `): od: # James A. Sellers, May 02 2005


CROSSREFS

Cf. A104206.
Sequence in context: A178635 A271189 A093272 * A093236 A146500 A271190
Adjacent sequences: A105344 A105345 A105346 * A105348 A105349 A105350


KEYWORD

nonn,base


AUTHOR

Parthasarathy Nambi, Apr 30 2005


EXTENSIONS

More terms from James A. Sellers, May 02 2005
Offset corrected by Michel Marcus, Aug 18 2017


STATUS

approved



