A269542 Aliquot sequence starting at 702.

702, 978, 990, 1818, 2160, 5280, 12864, 21680, 28912, 31848, 47832, 71808, 148512, 359520, 946848, 1895712, 4539360, 12180336, 23781648, 44267568, 76111632, 139130668, 104348008, 92030552, 80526748, 62286692, 55099864, 51042536, 47249404, 35492780, 39042100

Offset

0,1

Comments

This sequence is one of the first ones that contains numbers that exceed 2^64 and yet is known to terminate in a small prime followed by 1 and 0.

Note how all the numbers in the sequence are even, except the last 6 (not counting 0).

References

R. K. Guy, Unsolved Problems in Number Theory, B6.

Enoch Haga, Exploring Prime Numbers on Your PC, 2nd ed., 1998, pages 83-84 and Table 8, page 46. ISBN 1-885794-16-9.

Links

Daniel Mondot, Table of n, a(n) for n = 0..301

Formula

a(n+1) = A001065(a(n)). - R. J. Mathar, Oct 11 2017

Mathematica

NestWhileList[DivisorSigma[1, #]-#&, 702, #>0&] (* Paolo Xausa, Oct 16 2023 *)

Prog

(PARI) lista() = {print1(a=702, ", "); until (!a, a = sigma(a) - a; print1(a, ", "); ); } \\ Michel Marcus, Feb 29 2016

Crossrefs

Cf. A001065, A008888.

Sequence in context: A252574 A252575 A252566 * A237632 A304155 A305508

Adjacent sequences: A269539 A269540 A269541 * A269543 A269544 A269545

Keyword

nonn,fini,full

Author

Daniel Mondot, Feb 29 2016

Status

approved