login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A155089 Primes n such that odd nonprime = largest digit of concatenation of n and n-th prime. 0
17, 19, 29, 41, 43, 59, 79, 89, 97, 109, 127, 131, 139, 149, 157, 163, 167, 179, 191, 193, 197, 199, 211, 223, 229, 239, 251, 263, 269, 293, 317, 337, 349, 359, 373, 379, 389, 397, 401, 409, 419, 421, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Odd nonprime = 1 or 9.

LINKS

Table of n, a(n) for n=1..54.

EXAMPLE

If n=17=prime and 59=prime(17), then concatenation=1759(1<5<7<9=odd nonprime) and 17=a(1). If n=19=prime and 67=prime(19), then concatenation=1967(1<6<7<9=odd nonprime) and 19=a(2). If n=29=prime and 109=prime(29), then concatenation=29109(0<1<2<9=9=odd nonprime) and 29=a(3), etc.

CROSSREFS

Cf. A000027, A000040, A141468.

Sequence in context: A132246 A038969 A065742 * A101396 A050266 A045803

Adjacent sequences:  A155086 A155087 A155088 * A155090 A155091 A155092

KEYWORD

nonn,base

AUTHOR

Juri-Stepan Gerasimov, Jan 20 2009

EXTENSIONS

Entries checked by R. J. Mathar, May 10 2010

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 20 14:27 EDT 2019. Contains 322310 sequences. (Running on oeis4.)