A087341 Smallest prime which is a concatenation of n successive composite numbers.

89, 138140141, 87889091, 8890919293, 141516182021, 122123124125126128129, 121122123124125126128129, 707274757677788081, 21222425262728303233, 206207208209210212213214215216217, 405406407408410411412413414415416417

Offset

2,1

Comments

a(3) contains three digit composite numbers as every concatenation of two digit numbers n,n+2 and n+3 is == 0 (mod 7).

Links

Table of n, a(n) for n=2..12.

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 138140141.

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 87889091.

Example

a(2) = 89 is the concatenation of two successive composite numbers 8 and 9.
a(3) = 138140141 is the concatenation of 138,140 and 141.

Crossrefs

Cf. A002808.

Sequence in context: A243316 A072314 A087538 * A093405 A348166 A221307

Adjacent sequences: A087338 A087339 A087340 * A087342 A087343 A087344

Keyword

base,nonn

Author

Amarnath Murthy, Sep 06 2003

Extensions

More terms from David Wasserman, May 10 2005

Status

approved