The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 Cf. A129613, A225560 A226281, A226707. Sequence in context: A145598 A320392 A117881 * A161433 A180498 A107856 Adjacent sequences:  A161716 A161717 A161718 * A161720 A161721 A161722 KEYWORD nonn,more AUTHOR Robin Garcia, Jun 16 2013 EXTENSIONS a(10) from Giovanni Resta, Jun 16 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 10 02:28 EDT 2020. Contains 336367 sequences. (Running on oeis4.)