A136743 Number of prime factors in the n-th run of squarefree numbers.

2, 4, 3, 5, 1, 1, 5, 2, 5, 6, 5, 5, 3, 2, 1, 2, 5, 3, 6, 6, 3, 6, 3, 6, 1, 2, 6, 1, 5, 6, 6, 6, 4, 4, 1, 6, 4, 5, 6, 4, 1, 1, 5, 5, 2, 1, 6, 3, 4, 5, 6, 7, 4, 6, 1, 1, 6, 4, 7, 6, 6, 6, 3, 7, 1, 2, 6, 1, 5, 2, 1, 7, 6, 3, 7, 1, 1, 5, 3, 5, 8, 5, 1, 2, 4, 6, 2, 1, 6, 3, 6, 7, 4, 7, 4, 1, 2, 2, 6, 1, 6, 6, 2, 6, 5

Offset: 1

Author

Reinhard Zumkeller, Jan 20 2008

Keywords

• nonn

Comments

a(n) = A001221(A136742(n)) = A001222(A136742(n));

a(A136744(n)) = n and a(m) <> n for m < A136744(n).

Examples

			a(10)=A001221(A136742(10))=A001221(39270)=A001221(2*3*5*7*11*17)=6.
		

Links

• R. Zumkeller, Table of n, a(n) for n = 1..1000
• Eric Weisstein's World of Mathematics, Squarefree

Crossrefs

Cf. A005117.

Formula

a(n) = SUM(A001221(A072284(n)+k): 0<=k < A120992(n)).