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 A272476 a(n) = n if n is prime, a(n) = 2*n+3 otherwise. 1
 3, 5, 2, 3, 11, 5, 15, 7, 19, 21, 23, 11, 27, 13, 31, 33, 35, 17, 39, 19, 43, 45, 47, 23, 51, 53, 55, 57, 59, 29, 63, 31, 67, 69, 71, 73, 75, 37, 79, 81, 83, 41, 87, 43, 91, 93, 95, 47, 99, 101, 103, 105, 107, 53, 111, 113, 115, 117, 119, 59, 123, 61, 127 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Prime numbers repeated: 3, 5, 11, 19, 23, 31, 43, 47, 53, 59, 67, 71, ..., that is A065091 without A089531. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 MATHEMATICA Table[If[PrimeQ[n], n, 2 n + 3], {n, 0, 150}] PROG (MAGMA) [IsPrime(n) select n else 2*n+3: n in [0..80]]; CROSSREFS Cf. A000040, A018252. Cf. A061397, A191558. Sequence in context: A241429 A200109 A156060 * A205701 A218888 A261597 Adjacent sequences:  A272473 A272474 A272475 * A272477 A272478 A272479 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, May 02 2016 STATUS approved

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Last modified September 19 23:31 EDT 2019. Contains 327207 sequences. (Running on oeis4.)