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A129807 Primes congruent to +-7 mod 18. 6
7, 11, 29, 43, 47, 61, 79, 83, 97, 101, 137, 151, 173, 191, 223, 227, 241, 263, 277, 281, 313, 317, 331, 349, 353, 367, 389, 421, 439, 443, 457, 461, 479, 547, 569, 587, 601, 619, 641, 659, 673, 677, 691, 709, 727, 821, 839, 853, 857, 907, 911, 929, 947, 983, 997, 1019 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also: primes that are sums of three consecutive terms of A001651. These sum to either 3k+1+3k+2+3k+4=9k+7, candidates for A061241, or 3k+2+3k+4+3k+5=9k+11, candidates for A061238. - R. J. Mathar, Jun 10 2007

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Emma Lehmer, On special primes, Pac. J. Math., 118 (1985), 471-478.

FORMULA

Conjecture: Equals (A061241 UNION A061238) MINUS {2}. - R. J. Mathar, Jun 10 2007

MATHEMATICA

Select[Prime[Range[1000]], MemberQ[{7, 11}, Mod[ #, 18]]&] (* Zak Seidov, May 23 2007 *)

PROG

(MAGMA) [ p: p in PrimesUpTo(1300) | p mod 18 in {7, 11} ]; // Vincenzo Librandi, Aug 14 2012

CROSSREFS

Cf. A000040.

Cf. A001651, A061238, A061241.

Cf. A129805, A129806.

Sequence in context: A193867 A110572 A023254 * A045461 A153867 A153325

Adjacent sequences:  A129804 A129805 A129806 * A129808 A129809 A129810

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 22 2007

STATUS

approved

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Last modified December 12 07:31 EST 2019. Contains 329948 sequences. (Running on oeis4.)