A182720 Triangle read by rows: T(n,k) = A000041(k) if k divides n, T(n,k)=0 otherwise.

1, 1, 2, 1, 0, 3, 1, 2, 0, 5, 1, 0, 0, 0, 7, 1, 2, 3, 0, 0, 11, 1, 0, 0, 0, 0, 0, 15, 1, 2, 0, 5, 0, 0, 0, 22, 1, 0, 3, 0, 0, 0, 0, 0, 30, 1, 2, 0, 0, 7, 0, 0, 0, 0, 42, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 56, 1, 2, 3, 5, 0, 11, 0, 0, 0, 0, 0, 77, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 101, 1, 2, 0, 0, 0, 0, 15, 0, 0, 0, 0, 0, 0, 135, 1, 0, 3, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 176

Offset: 1

Author

Omar E. Pol, Nov 28 2010

Keywords

• nonn
• easy
• tabl

Examples

			1,
1, 2,
1, 0, 3,
1, 2, 0, 5,
1, 0, 0, 0, 7,
1, 2, 3, 0, 0, 11,
1, 0, 0, 0, 0, 0, 15,
1, 2, 0, 5, 0, 0, 0, 22,
1, 0, 3, 0, 0, 0, 0, 0, 30,
1, 2, 0, 0, 7, 0, 0, 0, 0, 42
		

Crossrefs

Cf. A000005, A000041, A051731, A168016, A168017, A168018, A168021. Positive integers of row n give A168017.

Row sums give A047968.

Programs

Maple

A182720 := proc(n,k) if n mod k = 0 then combinat[numbpart](k); else 0; end if ; end proc:
seq(seq(A182720(n,k),k=1..n),n=1..15) ;

Formula

T(n,k) = A051731(n,k)*A000041(k).