A177692 The even values of PrimePi(.), with repetition.

0, 2, 2, 4, 4, 4, 4, 6, 6, 6, 6, 8, 8, 8, 8, 10, 10, 12, 12, 12, 12, 14, 14, 14, 14, 16, 16, 16, 16, 16, 16, 18, 18, 18, 18, 18, 18, 20, 20, 22, 22, 22, 22, 24, 24, 24, 24, 24, 24, 24, 24, 26, 26, 28, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 32, 32, 32, 32, 32

Offset

1,2

Links

Table of n, a(n) for n=1..74.

Formula

Obtained by removing all odd numbers from A000720. Block lengths (frequencies of repetitions) are in A088680.

Crossrefs

Cf. A000720, A005843.

Sequence in context: A001670 A100144 A076222 * A098667 A279506 A105678

Adjacent sequences: A177689 A177690 A177691 * A177693 A177694 A177695

Keyword

nonn,easy

Author

Giovanni Teofilatto, May 11 2010

Extensions

Erroneous formula removed by R. J. Mathar, May 14 2010

Status

approved