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A259978 Terms in A053177 that are relatively prime to 3. 2
35, 95, 119, 143, 203, 215, 275, 299, 335, 395, 455, 515, 527, 539, 623, 635, 695, 707, 767, 779, 803, 899, 923, 935, 959, 1007, 1043, 1115, 1127, 1139, 1175, 1199, 1235, 1295, 1355, 1403, 1547, 1595, 1643, 1655, 1679, 1715, 1727, 1763, 1775, 1859, 1883, 1895 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
R. P. Boas & N. J. A. Sloane, Correspondence, 1974
FORMULA
a(n) = 2*A275770(n) + 1. - Hilko Koning, Jul 23 2018
MATHEMATICA
Select[2 Prime@ Range@ 162 + 1, CompositeQ@ # && GCD[3, #] == 1 &] (* Michael De Vlieger, Jul 13 2015 *)
PROG
(PARI) isok(n) = (n % 2) && !isprime(n) && isprime((n-1)/2) && (gcd(n, 3) == 1); \\ Michel Marcus, Jul 28 2018
CROSSREFS
Cf. A053177.
Sequence in context: A020164 A146206 A350196 * A044222 A044603 A063795
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jul 12 2015, following a suggestion from R. P. Boas, May 19 1974
EXTENSIONS
More terms from Lars Blomberg, Jul 13 2015
STATUS
approved

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Last modified July 25 02:50 EDT 2024. Contains 374585 sequences. (Running on oeis4.)