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A155036
Primes p = prime(c) with index c a composite such that the concatenation c//p is a prime.
0
7, 13, 37, 61, 103, 113, 149, 151, 181, 197, 199, 251, 263, 269, 271, 421, 439, 479, 487, 523, 631, 643, 653, 661, 677, 769, 811, 829, 853, 937, 947, 1019, 1039, 1049, 1051, 1277, 1319, 1399, 1427, 1489, 1543, 1663, 1753, 1759, 1831, 1867, 1901, 1933, 1949, 1999, 2039
OFFSET
1,1
EXAMPLE
The composite c=4 of A002808 addresses prime(4) = 7 and the concatenation 47 is a prime, which adds 7 to the sequence.
The composite c=6 addresses prime(6)=13 and the concatenation 613 is prime which adds 13 to the sequence.
CROSSREFS
KEYWORD
nonn,base,less
AUTHOR
EXTENSIONS
Edited and extended beyond 61 by R. J. Mathar, May 05 2010
STATUS
approved