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A161719 Least number k such that 7^(2^i) + k is prime for i = 0,1,..,n-1. 0
4, 4, 10, 40, 990, 8712, 1691820, 69466840, 6173190532, 4139897208540 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
a(5) = 990 because k = 990 is the minimal k such that N = 7^(2^i) + k is prime for i = 0, 1, 2, 3, 4; N = 997, 1039, 3391, 5765791, 33232930570591. But 7^(2^5) + 990 is divisible by 37 and four other primes.
CROSSREFS
Sequence in context: A320392 A117881 A342989 * A343090 A161433 A180498
KEYWORD
nonn,more
AUTHOR
Robin Garcia, Jun 16 2013
EXTENSIONS
a(10) from Giovanni Resta, Jun 16 2013
STATUS
approved

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Last modified March 19 07:19 EDT 2024. Contains 370954 sequences. (Running on oeis4.)