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 A078681 Start with n; iterate the process x -> ceiling(3x/2) until reach a prime. Sequence gives number of steps to reach a prime or 0 if no prime is ever reached. 1
 1, 1, 1, 53, 5, 52, 1, 4, 51, 2, 1, 3, 39, 50, 1, 162, 3, 2, 1, 38, 49, 4, 2, 161, 50, 2, 1, 52, 4, 37, 1, 48, 3, 13, 1, 160, 9, 49, 1, 8, 42, 51, 18, 3, 36, 8, 1, 47, 3, 2, 12, 35, 27, 159, 1, 8, 48, 2, 1, 7, 4, 41, 50, 16, 17, 2, 1, 35, 7, 13, 1, 46, 11, 2, 1, 3, 11, 34, 2, 26, 158, 7, 6, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS Table of n, a(n) for n=1..84. PROG (PARI) a(n)=if(n<0, 0, s=n; c=1; while(isprime(ceil(3*s/2))==0, s=ceil(3*s/2); c++); c) CROSSREFS Cf. A050412. Sequence in context: A198776 A051320 A232126 * A143294 A143428 A143385 Adjacent sequences: A078678 A078679 A078680 * A078682 A078683 A078684 KEYWORD nonn AUTHOR Benoit Cloitre, Dec 17 2002 STATUS approved

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Last modified December 8 17:58 EST 2023. Contains 367680 sequences. (Running on oeis4.)