[seqfan] Re: sigma(n) =

[юрий герасимов]

Dear SeqFans, also n such that:

4) sigma(n) = 1*sigma(n - 1): 15, 207, 958, ... (in OEIS is A231546)

5) sigma(n) = 2*sigma(n - 2): 120. 1560, 2940, 17760, 19920, 32220, 33840, 55965,
710040, 186780, 308040, 511500, 523776, 553500, 699360, 838215, ...

6) sigma(n) = 3*sigma(n - 3); 6, 30240, 242320, 3116960, 4044090, 6902280, ...

7) sigma(n) = 4*sigma(n - 4): 6, ....

8) sigma(n) = 5*sigma(n - 5). ?

юрий герасимов.

  09.11.2015, 18:42:11 пользователь юрий герасимов (2stepan at rambler.ru)
  написал:


  Dear SeqFans, n such that:

  1) sigma(n) = sigma(n - 2) + sigma(n + 2): 5160, 19080, 210336, 606420,
  1146720, 2382480, 3409140, ...

  2) sigma(n) = sigma(n - 2) - sigma(n + 2): 12812942, 45553367, 95028362, ...

  3) sigma(n) = sigma(n + 2) - sigma(n - 2): 358, 62494, 342238, 410638,
  8219473, 58463494, ...

  The sequences are "of general interest"?

  Best regards, JSG