A225175 Largest number which requires n iterations of the bi-unitary totient function (A116550) to reach 1.

1, 2, 3, 6, 10, 11, 12, 18, 30, 42, 78, 106, 210, 366, 550, 603, 750, 1290, 2562, 4398, 4305, 7470, 9090, 14322, 24558, 35382, 55482, 78020, 141190, 207519, 301642, 429870, 552693, 684846, 1060710, 1391390, 2385246, 3454044

Offset: 0

Author

N. J. A. Sloane, May 01 2013

Keywords

• nonn
• more

Comments

a(26) >= 55482. a(27) >= 78020. - R. J. Mathar, May 05 2013

References

• M. Lal, H. Wareham and R. Mifflin, Iterates of the bi-unitary totient function, Utilitas Math., 10 (1976), 347-350.

Crossrefs

Cf. A116550, A005424, A225176, A225174, A047994, A003271, A225172, A225173.

Extensions

a(26)-a(37) from Donovan Johnson, Dec 07 2013