A000173 Unitary-sociable numbers (smallest member of each cycle).

30, 1482, 2418, 24180, 35238, 263820, 395730, 473298, 698130, 763620, 2212026, 2233554, 172459210, 209524210, 341354790, 384121920, 525150234, 530946330, 582129630, 1799281330, 2069510520, 2514290520, 3344596854, 5251502340

Offset

1,1

Comments

If n=product p_i^a_i, d=product p_i^c_i is a unitary divisor of n if each c_i is 0 or a_i.

References

R. K. Guy, Unsolved Problems in Number Theory, 3rd edition, Sect. B7.

Links

Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 01 2006, Table of n, a(n) for n = 1..44

David Moews, Perfect, amicable and sociable numbers.

J. O. M. Pedersen, Tables of Aliquot Cycles. [Broken link]

J. O. M. Pedersen, Tables of Aliquot Cycles. [Via Internet Archive Wayback-Machine]

J. O. M. Pedersen, Tables of Aliquot Cycles. [Cached copy, pdf file only]

Eric Weisstein's World of Mathematics, Sociable Numbers.

Crossrefs

Cf. A034444, A003416, A097323.

Sequence in context: A048536 A369143 A318496 * A055351 A103917 A196464

Adjacent sequences: A000170 A000171 A000172 * A000174 A000175 A000176

Keyword

nonn,nice

Author

N. J. A. Sloane

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 01 2006

Status

approved