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

Author

Omar E. Pol, Mar 27 2008

Keywords

• easy
• fini
• full
• nonn

Examples

			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.