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 A228226 Integer lengths of log(2)-primes: numbers n such that the concatenation of the first n decimal digits of log(2) is prime. 1
 321, 466, 1271, 15690, 18872, 89973 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS No others <= 90220 - Eric W. Weisstein, Oct 28 2015 LINKS Table of n, a(n) for n=1..6. Eric Weisstein's World of Mathematics, Constant Primes Eric Weisstein's World of Mathematics, Integer Sequence Primes Eric Weisstein's World of Mathematics, Natural Logarithm of 2 Digits EXAMPLE log(2) = 0.6931471805... and the 321-digit number 6931...0641 is the smallest prime in the first digits, so a(1) = 321 CROSSREFS Cf. A002162 (decimal digits of log(2)). Sequence in context: A261262 A308527 A268517 * A004927 A074350 A144124 Adjacent sequences: A228223 A228224 A228225 * A228227 A228228 A228229 KEYWORD nonn,base,hard AUTHOR Eric W. Weisstein, Aug 17 2013 EXTENSIONS a(6) from Eric W. Weisstein, Oct 28 2015 STATUS approved

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Last modified June 1 22:32 EDT 2023. Contains 363078 sequences. (Running on oeis4.)