A342591 Numbers k such that A340740(k) <= k.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 28, 30, 32, 33, 34, 36, 40, 42, 46, 48, 54, 60, 78

Offset: 1

Author

J. M. Bergot and Robert Israel, Mar 16 2021

Keywords

• nonn
• more

Comments

Numbers k such that Sum_{1<=j<=k/2, j and k coprime} (k-j mod j) <= k.

Conjecture: these are all the terms.

The terms with A340740(k) = k are 19 and 48.

Examples

			a(7) = 7 is a term because A340740(7) = 2 <= 7.
		

Crossrefs

Cf. A340740

Programs

Maple

f:= proc(n) local k;
  add(`if`(igcd(k, n)=1, n mod k, 0), k=1..floor(n/2))
end proc:
select(t -> f(t) <= t, [$1..1000]);