A141409 Prime numbers that cannot be formed by the concatenation of previous terms.

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

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