A386417 Numbers k for which there exists at least one nondegenerate triangle with sides that are distinct divisors of k.

12, 20, 24, 30, 36, 40, 42, 48, 56, 60, 63, 70, 72, 80, 84, 88, 90, 96, 99, 100, 105, 108, 110, 112, 120, 126, 130, 132, 140, 144, 150, 154, 156, 160, 165, 168, 176, 180, 182, 189, 192, 195, 198, 200, 204, 208, 210, 216, 220, 224, 228, 234, 238, 240, 252, 255, 260

Offset: 1

Author

Felix Huber, Jul 28 2025

Keywords

• nonn

Comments

If k is a term, then m*k is also a term for all positive integers m.

Examples

			12 is a term because the sides of the nondegenerate triangles (2, 3, 4) and (3, 4, 6) are divisors of 12.
		

Links

• Felix Huber, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A027750, A378820, A386418.

Programs

Maple

A386417:=proc(n)
    option remember;
    local k,i;
    if n=1 then
        12
    else
        for k from procname(n-1)+1 do
            for i in combinat[choose](NumberTheory:-Divisors(k),3) do
                if i[3]A386417(n),n=1..25);