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 A049511 Numbers k such that prime(k) == 1 (mod 10). 9
 5, 11, 13, 18, 20, 26, 32, 36, 42, 43, 47, 53, 54, 58, 60, 64, 67, 79, 82, 83, 89, 94, 98, 100, 105, 110, 115, 116, 121, 125, 126, 133, 135, 141, 142, 152, 156, 160, 164, 167, 172, 173, 177, 178, 182, 190, 193, 194, 197, 202, 210, 212, 216, 218, 221, 230, 233 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also k for which prime(k) == 1 (mod 5). - Bruno Berselli, Mar 04 2016 The asymptotic density of this sequence is 1/4 (by Dirichlet's theorem). - Amiram Eldar, Mar 01 2021 LINKS Zak Seidov, Table of n, a(n) for n = 1..1000 FORMULA a(n) = A000720(A030430(n)). - Ray Chandler, Nov 07 2006 MATHEMATICA Select[Range[210], Mod[Prime[ # ], 10] == 1 &] (* Ray Chandler, Nov 07 2006 *) PROG (Sage) [n for n in (1..300) if Mod(nth_prime(n), 10) == 1] # Bruno Berselli, Mar 04 2016 (PARI) isok(n) = !((prime(n)-1) % 10); \\ Michel Marcus, Mar 04 2016 CROSSREFS Cf. A000720, A024912, A030430, A081759. Cf. A049508, A049509, A049510. Sequence in context: A226614 A328058 A191042 * A024900 A087490 A140565 Adjacent sequences: A049508 A049509 A049510 * A049512 A049513 A049514 KEYWORD nonn AUTHOR N. J. A. Sloane EXTENSIONS Extended by Ray Chandler, Nov 28 2003 Formula corrected by Zak Seidov, Sep 20 2011 STATUS approved

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Last modified September 30 18:47 EDT 2023. Contains 365793 sequences. (Running on oeis4.)