This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A168367 Terms of A123239 which are 2 mod 3. 3
 2, 11, 41, 59, 83, 107, 131, 179, 227, 251, 347, 419, 443, 467, 491, 563, 587, 659, 683, 761, 827, 947, 971, 1019, 1091, 1163, 1181, 1187, 1223, 1259, 1283, 1289, 1307, 1427, 1451, 1499, 1511, 1523, 1571, 1583, 1619, 1667, 1787, 1811, 1871, 1877 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Terms of A123239 which are also primes in Z(w) where w = (-1+sqrt(-3))/2 is a cube root of unity. LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 MATHEMATICA MangammalQ[p_] := Block[{k = 3}, While[k > 2, k = Mod[3 k, p]]; k != 2]; A168367 = Select[Prime[Range[290]], MangammalQ[#] && Mod[#, 3] == 2 &] (*Chandler*) PROG (PARI) is(n)=if(n<9, return(n==2)); if(n%6!=5 || !isprime(n) || znorder(Mod(3, n)) == n-1, return(0)); my(m=Mod(3, n)); while(m!=1, m*=3; if(m==2, return(0))); 1 \\ Charles R Greathouse IV, May 21 2017 CROSSREFS Cf. A003627, A123239, A168325. Sequence in context: A000822 A290175 A154813 * A247101 A080093 A175447 Adjacent sequences:  A168364 A168365 A168366 * A168368 A168369 A168370 KEYWORD nonn AUTHOR A.K. Devaraj, Nov 23 2009, Nov 25 2009 EXTENSIONS Extended by Ray Chandler, Jul 21 2011 Definition simplified by Charles R Greathouse IV, May 21 2017 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 December 15 15:42 EST 2018. Contains 318150 sequences. (Running on oeis4.)