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A117390
Numbers n such that 1234567890*sum(k=1,n,10^(10k-9)) + 1 is prime.
1
OFFSET
1,1
COMMENTS
The first two terms are given in the linked source in "Table 42: Ten Types of 'Rare' Prime Numbers" for entry "B. Sequential prime of the type: (1234567890)n 1", which designates that 1234567890 is concatenated n times and then 1 is appended. 1888, found by PrimeForm using recurrence mode, corresponds to an 18881-digit probable prime. There are no other terms <= 3000.
CROSSREFS
Sequence in context: A352282 A290763 A253417 * A141841 A146682 A146650
KEYWORD
bref,hard,more,nonn
AUTHOR
Rick L. Shepherd, May 03 2006
STATUS
approved