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

Author

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

Keywords

• nonn
• easy
• base

Comments

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

Examples

			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
		

Links

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

Crossrefs

Cf. A141033.

Programs

PARI

See Corneth link \\ David A. Corneth, Jan 23 2022

Extensions

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