A133425 Analog of A006684 for the 7x+1 problem (cf. A133421).

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

Offset: 1

Author

N. J. A. Sloane, Nov 27 2007

Keywords

• nonn

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, ...