A386418 a(n) is the number of nondegenerate triangles whose sides are distinct divisors of A386417(n).

2, 1, 5, 4, 6, 4, 2, 8, 3, 23, 1, 3, 19, 8, 14, 1, 17, 11, 1, 2, 3, 10, 2, 7, 57, 14, 1, 11, 13, 37, 9, 2, 8, 12, 1, 45, 4, 79, 3, 3, 14, 2, 7, 9, 5, 3, 45, 35, 11, 12, 4, 6, 1, 106, 62, 2, 8, 33, 1, 34, 3, 4, 41, 1, 3, 57, 4, 3, 50, 2, 6, 7, 25, 12, 16, 14, 30

Offset: 1

Author

Felix Huber, Jul 28 2025

Keywords

• nonn

Examples

			a(1) = 2 because there are exactly the 2 triangles (2, 3, 4) and (3, 4, 6) whose sides are distinct divisors of A386417(1) = 12.
		

Links

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

Crossrefs

Cf. A027750, A378820, A386417.

Programs

Maple

A386418:=proc(n)
    option remember;
    local a,k,i;
    if n=1 then
        [12,2]
    else
        for k from procname(n-1)[1]+1 do
            a:=0;
            for i in combinat[choose](NumberTheory:-Divisors(k),3) do
                if i[3]0 then
                return [k,a]
            fi
        od
    fi;
end proc;
seq(A386417(n)[2],n=1..77);