A134982 - OEIS

A134982

Number of elements in the n-th column of Medeleiev's periodic system of elements.

7, 6, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 6, 6, 6, 7

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OFFSET

1,1

COMMENTS

a(1)=7 represents Hydrogen and the alkali metals. Ends with a(32)=7 for 7 noble gases. These are the block counts (grouping) of the atomic numbers A134984. - R. J. Mathar, Feb 08 2008

The corresponding row numbers are A093907; the sum over all a(n) equals 118 in both cases. - R. J. Mathar, Feb 08 2008

Comment from Paul Curtz, May 03 2008 (Start):

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..29..30..31..32..33..34..35..36

37.38.39................................................40..41..42..43..44..45..46..47..48..49..50..51..52..53..54

55.56.57.58.59.60.61.62.63.64.65.66.67..68..69..70..71..72..73..74..75..76..77..78..79..80..81..82..83..84..85..86

87.88.89.90.91.92.93.94.95.96.97.98.99.100.101.102.103.104.105.106.107.108.109.110.111.112.113.114.115.116.117.118

(End)

LINKS

Table of n, a(n) for n=1..32.

CROSSREFS

Cf. A134984, A093907, A137583, A135559.

Sequence in context: A289266 A175996 A248940 * A064533 A131184 A021933

Adjacent sequences: A134979 A134980 A134981 * A134983 A134984 A134985

KEYWORD

nonn,fini,full

AUTHOR

Paul Curtz, Feb 05 2008

EXTENSIONS

Edited by R. J. Mathar, Feb 08 2008

STATUS

approved