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A153434
a(n) is the smallest number m such that all n numbers m+1, m.m+1, ..., m.m. ... .m+1 are prime, where dot means concatenation.
1
1, 2, 2, 42, 42, 1179990, 243464796
OFFSET
1,2
EXAMPLE
All 5 numbers 1+42,1+4242,1+424242,1+42424242 & 1+4242424242 are prime and 42
is the smallest such number so a(5)=42.
CROSSREFS
Cf. A153435.
Sequence in context: A116567 A215049 A087541 * A152016 A264516 A271845
KEYWORD
base,more,nonn
AUTHOR
Farideh Firoozbakht, Apr 01 2009
STATUS
approved