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

1,1

Comments

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

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

Links

R. Zumkeller, Table of n, a(n) for n = 1..1000

Eric Weisstein's World of Mathematics, Squarefree

Formula

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

Example

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

Crossrefs

Cf. A005117.

Sequence in context: A178938 A228196 A261326 * A011387 A019656 A256751

Adjacent sequences: A136740 A136741 A136742 * A136744 A136745 A136746

Keyword

nonn

Author

Reinhard Zumkeller, Jan 20 2008

Status

approved