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 A290541 Record gaps between numbers that are either prime or twice a prime. 3
 1, 3, 6, 10, 11, 12, 13, 15, 19, 21, 25, 28, 35, 40, 48, 57, 60, 64, 70, 75, 83, 90, 95, 117, 120, 144, 148, 150, 153, 167, 168, 196, 205, 212, 214, 221, 234, 244, 254, 255 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Records in A290496. The gap of 57 between 31397 and 31454 is due to the record prime gap between 31397 and 31469 being almost exactly twice the record prime gap between 15683 and 15727. LINKS FORMULA a(n) = A290489(n) - A290488(n). EXAMPLE a(3) = 6 because the next number that is a prime or twice a prime after 47 is 53, and that is a record gap of size 6. MATHEMATICA With[{nn = 10^7}, Union@ FoldList[Max, Differences@ #] &@ Union@ Flatten@ {#, 2 TakeWhile[#, # < Prime[nn]/2 &]} &@ Prime@ Range@ nn] (* Michael De Vlieger, Aug 06 2017 *) CROSSREFS Cf. A001751, A290488, A290489, A290496. Sequence in context: A307574 A169911 A073851 * A043321 A241858 A231668 Adjacent sequences:  A290538 A290539 A290540 * A290542 A290543 A290544 KEYWORD more,nonn AUTHOR Bobby Jacobs, Aug 05 2017 EXTENSIONS a(36)-a(40) from Giovanni Resta, Aug 06 2017 STATUS approved

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Last modified December 13 22:55 EST 2019. Contains 329974 sequences. (Running on oeis4.)