

A213312


Numbers with exactly 5 nonprime substrings (substrings with leading zeros are considered to be nonprime).


1



101, 102, 105, 109, 110, 114, 116, 118, 120, 121, 124, 126, 128, 141, 142, 145, 149, 150, 154, 156, 158, 161, 162, 165, 181, 182, 185, 187, 189, 190, 194, 196, 198, 200, 201, 204, 206, 208, 209, 210, 214, 216, 218, 240
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OFFSET

1,1


COMMENTS

The sequence is finite. Proof: Each 7digit number has at least 6 nonprime substrings. Thus, each number with more than 7 digits has >= 6 nonprime substrings, too. Consequently, there is a boundary b<10^6, such that all numbers > b have more than 5 nonprime substrings.
The first term is a(1)=101=A213302(5). The last term is a(1330)=831373=A213300(5).


LINKS



EXAMPLE

a(1)=101, since 101 has 5 nonprime substrings (0, 01, 1, 1, 10).
a(1330)= 831373, since there are 5 nonprime substrings (1, 8, 831, 8313, 31373).


CROSSREFS



KEYWORD

nonn,fini,base


AUTHOR



STATUS

approved



