A213319 Numbers with exactly 12 nonprime substrings (substrings with leading zeros are considered to be nonprime).

10023, 10053, 10067, 10073, 10079, 10093, 10097, 10107, 10112, 10115, 10119, 10122, 10125, 10129, 10141, 10143, 10147, 10152, 10155, 10170, 10174, 10176, 10178, 10181, 10183, 10190, 10194, 10196, 10198, 10212, 10215, 10219

Offset

1,1

Comments

The sequence is finite. Proof: Each 9-digit number has at least 15 nonprime substrings. Thus, each number with more than 9 digits has >= 15 nonprime substrings, too. Consequently, there is a boundary b<10^9, such that all numbers > b have more than 12 nonprime substrings.

The first term is a(1)=10023=A213302(12). The last term is a(51477)=99733313=A213300(12).

Links

Hieronymus Fischer, Table of n, a(n) for n = 1..51477

Example

a(1)=10023, since 10023 has 12 nonprime substrings (0, 0, 1, 00, 02, 10, 002, 023, 100, 0023, 1002, 10023).
a(51477)=99733313, since there are 11 nonprime substrings (1, 9, 9, 33, 33, 99, 333, 973, 33313, 97333, 733313, 99733313).

Crossrefs

Cf. A019546, A035232, A039996, A046034, A069489, A085823, A211681, A211682, A211684, A211685.

Cf. A035244, A079307, A213300 - A213321.

Sequence in context: A146505 A202653 A210130 * A241880 A245209 A205822

Adjacent sequences: A213316 A213317 A213318 * A213320 A213321 A213322

Keyword

nonn,fini,base

Author

Hieronymus Fischer, Aug 26 2012

Status

approved