1,1

This sequence together with A001359 gives the solutions of sigma(x)+2=sigma(x+2).

Sivaramakrishnan, R. (1989): Classical Theory of Arithmetical Functions, M. Dekker Inc., New York-Basel, p. 81, Problem 12.

These 3 solutions are from Makowski, according to Sivaramakrishnan, R. (1989).

sigma(434)+2=770=sigma(434+2), so 434 is in the sequence.

Cf. A000203, A001359, A054799.

Sequence in context: A055009 A054982 A108785 this_sequence A054987 A054905 A124043

Adjacent sequences: A050504 A050505 A050506 this_sequence A050508 A050509 A050510

nonn,bref

Jud McCranie (j.mccranie(AT)comcast.net), Dec 27 1999

No others < 4290000000.