A335859 Terms of A334245 in increasing order and without repetition.

12, 15, 21, 30, 35, 57, 60, 65, 70, 77, 91, 105, 111, 114, 119, 126, 133, 143, 147, 150, 155, 165, 168, 180, 185, 190, 198, 209, 217, 220, 231, 234, 255, 260, 264, 294, 301, 310, 312, 319, 323, 330, 341, 360, 427, 432, 437, 455, 456, 462, 473, 497, 504, 510, 511, 546, 559, 588

Offset

1,1

Comments

See the network with the 50 smallest merging points of A334245 in link.

Links

Robert Israel, Table of n, a(n) for n = 1..5939

Bernard Schott and Blandine Schott, Network of merging points.

Example

l means: add least prime factor, and,
L means: add largest prime factor.
For 3:
   L:  3 + 3 = 6            l: 3 + 3 = 6
   l:  6 + 2 = 8            L: 6 + 3 = 9
   L:  8 + 2 = 10           l: 9 + 3 = 12
   l: 10 + 2 = 12
So A334245(3) = 12 and 12 is a merging point with a(1) = 12.
Now, for 12:
   L: 12 + 3 = 15           l: 12 + 2 = 14
   l: 15 + 3 = 18           L: 14 + 7 = 21
   L: 18 + 3 = 21
So A334245(12) = 21 and 21 is the merging point corresponding to 12 with a(3) = 21.

Maple

N:= 1000: # to get all values <= N
S:= x -> x + min(numtheory:-factorset(x)):
T:= x -> x + max(numtheory:-factorset(x)):
f:= proc(n) g(S(n), T(n), 0, 1) end proc:
g:= proc(s, t, i, j) option remember;
      if max(s, t) > N then return 0 fi;
      if s = t and i=j then return s fi;
      if s <= t then
        if i = 0 then procname(T(s), t, 1, j)
        else procname(S(s), t, 0, j)
        fi
      elif j=0 then procname(s, T(t), i, 1)
      else procname(s, S(t), i, 0)
      fi
end proc:
sort(convert(map(f, {$2..N}) minus {0}, list)); # Robert Israel, Jul 09 2020

Crossrefs

Cf. A334245.

Sequence in context: A162820 A267195 A353702 * A259040 A158190 A122040

Adjacent sequences: A335856 A335857 A335858 * A335860 A335861 A335862

Keyword

nonn

Author

Bernard Schott, Jun 27 2020

Status

approved