A168497 The halfs of even single (or even isolated) numbers.

1, 2, 3, 6, 9, 15, 21, 30, 36, 51, 54, 69, 75, 90, 96, 99, 114, 120, 135, 141, 156, 174, 210, 216, 231, 261, 285, 300, 309, 321, 330, 405, 411, 414, 429, 441, 510, 516, 525, 531, 546, 576, 615, 639, 645, 651, 660, 714, 726, 741, 744, 804, 810, 834, 849, 861, 894

Offset

1,2

Comments

Essentially the same as A040040: 1, followed by A040040. - Joerg Arndt, Jun 18 2015

Even single (or isolated) numbers/2. Unit together with (average of twin prime pairs (A014574), divided by 2).

Links

Table of n, a(n) for n=1..57.

Formula

a(n)=A167777(n)/2.

Crossrefs

Cf. A040040, A167777.

Sequence in context: A308870 A273371 A040040 * A256975 A364841 A355980

Adjacent sequences: A168494 A168495 A168496 * A168498 A168499 A168500

Keyword

nonn

Author

Juri-Stepan Gerasimov, Nov 27 2009

Extensions

Entries checked by R. J. Mathar, Apr 14 2010

Status

approved