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A152136
a(0) = 0; thereafter a(n) is always the smallest integer > a(n-1) not leading to a contradiction, such that the concatenation of any two consecutive digits in the sequence is a prime.
10
0, 2, 3, 7, 9, 71, 73, 79, 711, 713, 717, 971, 973, 1111, 1113, 1117, 1119, 7111, 7113, 7117, 9711, 9713, 11111, 11113, 11117, 11119, 71111, 71113, 71117, 97111, 97113, 111111, 111113, 111117, 111119, 711111, 711113, 711117, 971111
OFFSET
0,2
COMMENTS
A variant of A152607 suggested by Zak Seidov, Sep 24 2009.
Computed by Jean-Marc Falcoz.
Comment from Jean-Marc Falcoz: (Start)
The sequence is infinite since it has the following structure:
9713, 11111, 11113, 11117, 11119, 71111, 71113, 71117, 97111,
97113, 111111, 111113, 111117, 111119, 711111, 711113, 711117, 971111,
971113, 1111111, 1111113, 1111117, 1111119, 7111111, 7111113, 7111117, 9711111,
9711113, 11111111, 11111113, 11111117, 11111119, 71111111, 71111113, 71111117, 97111111,
97111113, 111111111, 111111113, 111111117, 111111119, 711111111, 711111113, 711111117, 971111111,
971111113, 1111111111, 1111111113, 1111111117, 1111111119, 7111111111, 7111111113, 7111111117, 9711111111,
9711111113, ... (End)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Sep 24 2009
EXTENSIONS
Offset changed by N. J. A. Sloane, Jun 16 2021
STATUS
approved