A088825 Numbers n such that the sum of largest prime factors of numbers from 1 to n is divisible by n.

1, 2, 8, 9, 32, 62, 558, 993, 995, 1947, 2150, 4343, 9944, 10977, 43054658, 202275890, 2291937393, 2459073795, 2836929091, 3737529738, 21382629569, 248208997602, 389691028017, 838566394212, 1019000924619

Offset

1,2

Comments

a(21) > 15*10^9. - Donovan Johnson, Nov 01 2009

a(22) > 10^11. - Donovan Johnson, Jul 09 2010

a(26) > 5*10^12. - Giovanni Resta, Apr 25 2017

Links

Table of n, a(n) for n=1..25.

Formula

Solutions to Mod[A088822[x], x]=0.

Mathematica

gp[n_] := If[n==1, 0, FactorInteger[n][[-1, 1]]]; Flatten@ Position[ Accumulate[ gp /@ Range[10^5]] / Range[10^5], _Integer] (* Giovanni Resta, Apr 25 2017 *)

Crossrefs

Cf. A088821-A088824.

Sequence in context: A163619 A166968 A075644 * A337706 A368341 A369649

Adjacent sequences: A088822 A088823 A088824 * A088826 A088827 A088828

Keyword

nonn

Author

Labos Elemer, Oct 22 2003

Extensions

More terms from Ray Chandler, Oct 31 2003

a(17)-a(20) from Donovan Johnson, Nov 01 2009

a(21) from Donovan Johnson, Jul 09 2010

a(22)-a(25) from Giovanni Resta, Apr 25 2017

Status

approved