



1, 7, 11, 19, 31, 43, 163, 283, 403, 1111, 1123, 1243, 1303, 1549, 1963, 4123, 9643, 10003, 11539, 21431, 76963, 97031, 468109, 1351963, 4553323, 4778471, 5163139, 6563551, 7618843, 45214123, 65704243, 161738803, 202903723
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OFFSET

1,2


COMMENTS

The 7x+1 map sends x to x/2 if x is even, x/3 if x is divisible by 3, x/5 if x is divisible by 5, otherwise 7x+1.


LINKS

N. J. A. Sloane, Table of n, a(n) for n=1..53 (from the web page of Tomás Oliveira e Silva)
Tomás Oliveira e Silva, The px+1 problem
Index entries for sequences related to 3x+1 (or Collatz) problem


CROSSREFS

Cf. A133421, A133426, A133419, ...
Sequence in context: A032672 A235806 A238501 * A103802 A038984 A165549
Adjacent sequences: A133422 A133423 A133424 * A133426 A133427 A133428


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Nov 27 2007


STATUS

approved



