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 A080309 n-th even number equals n-th multiple of a Fermat number. 2
 3, 5, 6, 9, 10, 12, 15, 17, 24, 25, 27, 30, 33, 34, 39, 40, 42, 45, 48, 50, 51, 60, 63, 65, 66, 68, 69, 70, 72, 75, 78, 80, 81, 95, 96, 111, 119, 120, 123, 125, 126, 129, 130, 132, 135, 136, 144, 159, 160, 174, 175, 177, 180, 183, 185, 186, 187, 189, 190, 192, 195, 204 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Sequence includes only multiples of Fermat numbers (sequence A080307), but not all of them. It is not certain that A080309 is infinite, but it seems likely given that exactly one-half of all integers are multiples of Fermat numbers (see A080307). LINKS EXAMPLE The first 3 even numbers are 2, 4 and 6; the first 3 multiples of Fermat numbers (the numbers of the form 2^(2^n)+1) are 3, 5 and 6. The third even number is also the third Fermat multiple; thus 3 is in the sequence. CROSSREFS Cf. A000215 (the Fermat numbers), A080307. Sequence in context: A001969 A075311 A032786 * A281746 A287162 A018900 Adjacent sequences:  A080306 A080307 A080308 * A080310 A080311 A080312 KEYWORD nonn AUTHOR Matthew Vandermast, Feb 16 2003 STATUS approved

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Last modified April 16 05:26 EDT 2021. Contains 343030 sequences. (Running on oeis4.)