A138718 Group number of the elements of the n-th column of the periodic table of the elements with 18 columns.

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

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Example

Columns of The Periodic Table of the Elements:
1...2...3...4...5...6...7...8...9...10..11..12..13..14..15..16..17..18.
A notation convention of the groups is
1A, 2A, 3B, 4B, 5B, 6B, 7B, 8B, 8B, 8B, 1B, 2B, 3A, 4A, 5A, 6A, 7A, 8A.
Then the sequence of this entry is formed from the numeric characters: 1, 2, 3, 4, 5, 6, 7, 8, 8, 8, 1, 2, ...
Note that the elements, of the 4th period, whose crystals are ferromagnetics (26=Fe=Iron, 27=Co=Cobalt and 28=Ni=Nickel) are in the group 8B.

Crossrefs

Cf. A138723, A138724.

Sequence in context: A063278 A355459 A110011 * A328289 A108922 A373195

Adjacent sequences: A138715 A138716 A138717 * A138719 A138720 A138721

Keyword

easy,fini,full,nonn

Author

Omar E. Pol, Mar 27 2008

Status

approved