The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A219048 Numbers k such that 3^k + 32 is prime. 16
 2, 3, 4, 6, 23, 24, 38, 164, 172, 176, 207, 216, 251, 272, 424, 1112, 1318, 2072, 2664, 3143, 4704, 5236, 9526, 13064, 13523, 27111, 35931, 37504, 47542, 128656, 181551 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(32) > 2*10^5. - Robert Price, Nov 15 2013 LINKS Table of n, a(n) for n=1..31. EXAMPLE For k = 2, 3^2 + 32 = 41 (prime). Hence k = 2 is in the sequence. MATHEMATICA Do[If[PrimeQ[3^n + 32], Print[n]], {n, 10000}] PROG (PARI) is(n)=isprime(3^n+32) \\ Charles R Greathouse IV, Feb 17 2017 CROSSREFS Cf. Sequences of numbers k such that 3^k + m is prime: (m = 2) A051783, (m = -2) A014224, (m = 4) A058958, (m = -4) A058959, (m = 8) A217136, (m = -8) A217135, (m = 10) A217137, (m = -10) A217347, (m = 14) A219035, (m = -14) A219038, (m = 16) A205647, (m = -16) A219039, (m = 20) A219040, (m = -20) A219041, (m = 22) A219042, (m = -22) A219043, (m = 26) A219044, (m = -26) A219045, (m = 28) A219046, (m = -28) A219047, (m = 32) A219048, (m = -32) A219049, (m = 34) A219050, (m = -34) A219051. Note that if m is a multiple of 3, 3^k + m is also a multiple of 3 (for k greater than 0), and as such isn't prime. Sequence in context: A217351 A274238 A115035 * A329577 A217442 A065199 Adjacent sequences: A219045 A219046 A219047 * A219049 A219050 A219051 KEYWORD nonn,more AUTHOR Nicolas M. Perrault, Nov 10 2012 EXTENSIONS a(23)-a(31) from Robert Price, Nov 15 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 12 10:12 EDT 2024. Contains 374239 sequences. (Running on oeis4.)