A068681 Primes formed by the concatenation n, n-2, n.

313, 757, 131113, 171517, 312931, 393739, 474547, 494749, 575557, 939193, 111109111, 127125127, 139137139, 147145147, 151149151, 169167169, 189187189, 213211213, 217215217, 227225227, 237235237, 239237239, 247245247, 253251253, 269267269, 331329331, 333331333, 353351353, 363361363, 377375377, 387385387, 389387389, 393391393

Offset

1,1

Links

Table of n, a(n) for n=1..33.

Example

111109111 is a term as it is the concatenation of 111, 109 and 111.

Crossrefs

Cf. A068680.

Sequence in context: A104719 A087364 A090514 * A341802 A082436 A108845

Adjacent sequences: A068678 A068679 A068680 * A068682 A068683 A068684

Keyword

base,easy,nonn

Author

Amarnath Murthy, Mar 02 2002

Extensions

More terms from Eli McGowan (ejmcgowa(AT)mail.lakeheadu.ca), Apr 11 2002

Status

approved