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 A049386 Binary order of 2^n-th prime. 1
 1, 2, 3, 5, 6, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Jinyuan Wang, Table of n, a(n) for n = 0..78 FORMULA a(n) = A029837(A033844(n)). a(n) = ceiling(log_2(prime(2^n))). EXAMPLE The 549755813888th = (2^39)th prime is 16149760533341, whose binary order is 44: it is ceiling(43.87657801)=44, so a(39)=44; a(0)=1 is the binary order of the (2^0)th = 1st prime (= 2), which is log_2(2) = 1. PROG (PARI) a(n) = ceil(log(prime(2^n))/log(2)); \\ Michel Marcus, Aug 07 2021 CROSSREFS Cf. A006988, A029837, A033844. Sequence in context: A039249 A039191 A214329 * A188320 A039143 A039104 Adjacent sequences: A049383 A049384 A049385 * A049387 A049388 A049389 KEYWORD nonn AUTHOR Labos Elemer EXTENSIONS a(40)-a(57) from Michel Marcus, Aug 25 2019 More terms from Jinyuan Wang, Aug 07 2021 STATUS approved

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Last modified September 10 19:10 EDT 2024. Contains 375794 sequences. (Running on oeis4.)