A125737 Numbers that appear in the successive application of the sequence A125736 (sum of the neighbors integer-log).

21, 22, 28, 29, 33, 38, 53

Offset

0,1

Comments

There are two cycles (28 38 53) and (21 22 33 29), that are the attractors in this fixed point iteration.

Links

Table of n, a(n) for n=0..6.

Example

nilog(28)=ilog(27)+ilog(29)=ilog(3^3)+ilog(29)=3*3+29=38.
nilog(38)=ilog(37)+ilog(39)=ilog(37)+ilog(13*3)=37+(13+3)=53.
nilog(53)=ilog(52)+ilog(54)=ilog(2^2*13)+ilog(2*3^3)=(2*2+13)+(2+3*3)=28.

Mathematica

f[n_] := Plus @@ Times @@@ FactorInteger@ n; f[1] = 0; g[n_] := f[n - 1] + f[n + 1]; Union[ Nest[g, #, 31] & /@ Range[3, 500000]]

Crossrefs

Sequence in context: A333908 A241851 A295747 * A349248 A160782 A022391

Adjacent sequences: A125734 A125735 A125736 * A125738 A125739 A125740

Keyword

fini,nonn

Author

Carlos Alves, Dec 02 2006

Status

approved