1,2

The largest member of the second group is given by A092979(n).

Table of n, a(n) for n=1..20.

For n = 3 the groups are (1,2,3), (4,5), (6) so a(3)= 3.

For n = 4 the groups are (1,2,3,4),(5,6),(7,8),(9,10),(11,12),(13,14),(15,16),(17,18),(19,20),(21,22),(23,24),(25), so a(4) = 12.

For n = 7 the groups are (1,2,3,4,5,6,7), (8,9,10,11), (12,13,14,15),(16,17,18,19),(20,21,22),(23,24,25),(26,27,28),... so a(7)= 2507.

Cf. A092979.

Sequence in context: A083746 A025231 A094532 * A191464 A052183 A123899

Adjacent sequences: A092977 A092978 A092979 * A092981 A092982 A092983

nonn

Bobby L. Wilson (bwilson4(AT)radar.gsw.edu), following a suggestion of Amarnath Murthy, Jun 05 2004

More terms from John W. Layman, Nov 18 2004

Further terms from William Rex Marshall, Jun 22 2005

approved