login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A141409 Prime numbers that cannot be formed by the concatenation of previous terms. 6
2, 3, 5, 7, 11, 13, 17, 19, 29, 31, 41, 43, 47, 59, 61, 67, 71, 79, 83, 89, 97, 101, 103, 107, 109, 127, 131, 139, 149, 151, 157, 163, 167, 179, 181, 191, 199, 223, 227, 233, 239, 251, 263, 269, 277, 281, 307, 337, 349, 353, 373, 401, 409, 419, 421, 431, 439, 443, 449, 457, 461 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Previous terms can appear in any order but can be used at most once. - Paolo P. Lava, Mar 04 2010

LINKS

David A. Corneth, Table of n, a(n) for n = 1..10000

David A. Corneth, PARI program

EXAMPLE

137 is not in the sequence because 13 || 7 -> 137;

797 is not in the sequence because 7 || 97 or 79 || 7 -> 797.

257 is not in the sequence because 2 || 5 || 7 = 257 where || denotes concatenation. - David A. Corneth, Jan 23 2022

PROG

(PARI) See Corneth link \\ David A. Corneth, Jan 23 2022

CROSSREFS

Cf. A141033.

Sequence in context: A092570 A133956 A176164 * A238647 A348358 A171821

Adjacent sequences:  A141406 A141407 A141408 * A141410 A141411 A141412

KEYWORD

nonn,easy,base

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Aug 04 2008, Aug 28 2008, Mar 04 2010

EXTENSIONS

Offset changed to 1 and data corrected by David A. Corneth, Jan 23 2022

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 28 20:34 EDT 2022. Contains 357081 sequences. (Running on oeis4.)