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 A179627 a(n) = length of Collatz sequence starting with n-th prime 1
 2, 6, 5, 12, 11, 8, 10, 15, 12, 14, 68, 16, 70, 21, 67, 10, 23, 15, 20, 66, 74, 25, 71, 22, 76, 19, 57, 65, 73, 11, 32, 21, 59, 29, 18, 13, 26, 18, 45, 23, 23, 15, 31, 77, 20, 77, 28, 47, 12, 25, 55, 36, 17, 44, 79, 52, 22, 30, 14, 30, 41, 76, 27, 57, 84, 27, 19, 73, 81, 24, 81 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 Eric Weisstein's World of Mathematics, Collatz Problem Wikipedia, Collatz conjecture Index entries for sequences related to 3x+1 (or Collatz) problem FORMULA a(n) = A006666(A000040(n)) + 1. [Reinhard Zumkeller, Apr 03 2012] EXAMPLE For n=4 the a(n)=12 because the fourth prime is 7 and if you start with 7, the 12th term of syracuse-sequence is 1. The syracuse-sequence starting with 7 has the dimension 12. PROG (Haskell) a179627 = (+ 1) . a006666 . a000040 -- Reinhard Zumkeller, Apr 03 2012 CROSSREFS Sequence in context: A077174 A211201 A359035 * A193977 A092313 A318358 Adjacent sequences: A179624 A179625 A179626 * A179628 A179629 A179630 KEYWORD nonn AUTHOR Roland Schroeder (florola(AT)gmx.de), Jul 21 2010 EXTENSIONS Offset fixed by Reinhard Zumkeller, Apr 03 2012 STATUS approved

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Last modified July 24 20:30 EDT 2024. Contains 374585 sequences. (Running on oeis4.)