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A113868
Numbers k such that (k+1)^9 - 3 is prime.
2
1, 19, 21, 45, 73, 75, 103, 109, 111, 139, 195, 205, 211, 321, 331, 385, 433, 439, 571, 601, 763, 765, 805, 811, 819, 985, 1069, 1075, 1159, 1333, 1395, 1401, 1431, 1459, 1573, 1629, 1635, 1659, 1759, 1801, 2025, 2035, 2065, 2079, 2131, 2133, 2191, 2199
OFFSET
1,2
LINKS
FORMULA
a(n) = A112405(n) - 1. - Daniel Starodubtsev, Feb 10 2020
EXAMPLE
If k=139 then (139+1)^9 - 3 = 20661046783999999997 (prime).
MATHEMATICA
Do[If[PrimeQ[(n + 1)^9 - 3], Print[n]], {n, 1, 2200}] (Steinerberger)
PROG
MAGMA) [n: n in [1..100000] | IsPrime((n+1)^9-3)]; // Vincenzo Librandi, Nov 13 2010
(PARI) is(n)=isprime((n+1)^9-3) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Cf. A112405.
Sequence in context: A178889 A167998 A050714 * A056025 A284670 A099954
KEYWORD
nonn,easy
AUTHOR
Parthasarathy Nambi, Jan 25 2006
EXTENSIONS
More terms from Stefan Steinerberger, Jan 27 2006
STATUS
approved