|
| |
|
|
A019549
|
|
Primes formed by concatenating other primes.
|
|
6
| |
|
|
23, 37, 53, 73, 113, 137, 173, 193, 197, 211, 223, 227, 229, 233, 241, 257, 271, 277, 283, 293, 311, 313, 317, 331, 337, 347, 353, 359, 367, 373, 379, 383, 389, 397, 433, 523, 541, 547, 557, 571, 577, 593, 613, 617, 673, 677, 719, 727, 733, 743, 757, 761, 773, 797, 977
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
REFERENCES
| Sylvester Smith, "A Set of Conjectures on Smarandache Sequences", Bulletin of Pure and Applied Sciences, (Bombay, India), Vol. 15 E (No. 1), 1996, pp. 101-107.
|
|
|
LINKS
| M. F. Hasler, Table of n, a(n) for n=1,...,17495
M. L. Perez et al., eds., Smarandache Notions Journal
|
|
|
EXAMPLE
| 113 is member as 11 and 3 are primes.
a(12)=227 = "2"+"2"+"7" is the first term not in A105184 (restricted to concatenation of two primes). [From M. F. Hasler (www.univ-ag.fr/~mhasler), Oct 15 2009]
|
|
|
PROG
| (PARI) is_A019549(n, recurse=0)={ isprime(n) == recurse & return(recurse); for(i=1, #Str(n)-1, isprime( n%10^i ) & is_A019549( n\10^i, 1) & n\10^(i-1)%10 & return(1)) } [Hasler]
|
|
|
CROSSREFS
| Cf. A105184.
Cf. A152242. [From M. F. Hasler (www.univ-ag.fr/~mhasler), Oct 15 2009]
Sequence in context: A051362 A034302 A057878 * A129800 A105184 A066064
Adjacent sequences: A019546 A019547 A019548 * A019550 A019551 A019552
|
|
|
KEYWORD
| nonn,base
|
|
|
AUTHOR
| R. Muller
|
| |
|
|
