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 A013606 a(n) = 4^n - prevprime(4^n). 2
 1, 3, 3, 5, 3, 3, 3, 15, 5, 3, 3, 3, 5, 57, 35, 5, 41, 5, 45, 87, 11, 17, 21, 59, 27, 47, 33, 5, 27, 93, 57, 59, 5, 23, 35, 93, 35, 15, 11, 65, 57, 35, 35, 299, 33, 83, 3, 17, 51, 15, 33, 17, 117, 59, 21, 75, 11, 3, 5, 119, 3, 59, 137, 159, 5, 347, 45, 113, 105, 27, 111 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Daniel Starodubtsev, Table of n, a(n) for n = 1..1000 FORMULA a(n) = A000302(n) - A104089(n). - Michel Marcus, Sep 01 2019 MAPLE seq(4^i-prevprime(4^i), i=1..100); MATHEMATICA #-NextPrime[#, -1]&/@(4^Range[80]) (* Harvey P. Dale, Dec 13 2016 *) PROG (PARI) a(n) = 4^n - precprime(4^n); \\ Michel Marcus, Sep 01 2019 CROSSREFS Cf. A000302, A104089. Sequence in context: A333596 A066670 A282270 * A206550 A284723 A190911 Adjacent sequences: A013603 A013604 A013605 * A013607 A013608 A013609 KEYWORD nonn AUTHOR James Kilfiger (mapdn(AT)csv.warwick.ac.uk) STATUS approved

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Last modified December 9 23:05 EST 2022. Contains 358710 sequences. (Running on oeis4.)