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 A067533 Numbers k such that both k - tau(k) and k + tau(k) are prime where tau(k) = A000005(k). 1
 5, 15, 27, 33, 57, 93, 105, 165, 177, 189, 231, 237, 245, 267, 275, 285, 345, 375, 393, 425, 453, 555, 567, 573, 597, 609, 637, 651, 687, 723, 833, 933, 1005, 1025, 1095, 1167, 1209, 1221, 1227, 1293, 1311, 1431, 1445, 1479, 1491, 1527, 1551, 1563, 1573 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Marius A. Burtea, Table of n, a(n) for n = 1..1128 EXAMPLE 57 is a term as tau(57) = 4 and 57-4 = 53 and 57+4 = 61 are both primes. PROG (PARI) isok(n) = my(nd = numdiv(n)); isprime(n-nd) && isprime(n+nd); \\ Michel Marcus, Oct 12 2018 CROSSREFS Intersection of A067531 and A067532. Sequence in context: A147426 A100437 A339567 * A110343 A146060 A076843 Adjacent sequences: A067530 A067531 A067532 * A067534 A067535 A067536 KEYWORD easy,nonn AUTHOR Amarnath Murthy, Feb 17 2002 EXTENSIONS More terms from Sascha Kurz, Mar 19 2002 Offset corrected by Alois P. Heinz, Oct 10 2018 Name changed by David A. Corneth, Oct 12 2018 STATUS approved

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Last modified June 4 03:55 EDT 2023. Contains 363118 sequences. (Running on oeis4.)