A068655 Primes which are a concatenation of at least two consecutive primes.

23, 2357, 3137, 5711, 8389, 111317, 151157, 157163, 167173, 171923, 199211, 233239, 251257, 257263, 263269, 271277, 313741, 331337, 353359, 373379, 414347, 433439, 467479, 509521, 523541, 541547, 601607, 653659, 661673, 677683, 727733

Offset

1,1

Links

Table of n, a(n) for n=1..31.

Example

111317 is a term as it is a concatenation of 11, 13 and 17. 199211 is a term as a concatenation of 199 and 211.

Mathematica

Module[{pr=Prime[Range[500]], c2, c3, c4}, c2=Select[FromDigits/@ (Flatten[ IntegerDigits[ #], 1]&/@Partition[pr, 2, 1]), PrimeQ]; c3=Select[ FromDigits/@ (Flatten[IntegerDigits[#], 1]&/@Partition[pr, 3, 1]), PrimeQ]; c4= Select[ FromDigits/@(Flatten[IntegerDigits[#], 1]&/@Partition[ pr, 4, 1]), PrimeQ]; Take[Union[Join[c2, c3, c4]], 50]] (* Harvey P. Dale, Apr 20 2017 *)

Crossrefs

Sequence in context: A220653 A281787 A132937 * A336170 A232362 A233226

Adjacent sequences: A068652 A068653 A068654 * A068656 A068657 A068658

Keyword

base,nonn

Author

Amarnath Murthy, Feb 28 2002

Extensions

Edited by Larry Reeves (larryr(AT)acm.org), Oct 09 2003

Status

approved