This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A134982 #7 Mar 31 2012 21:08:03 %S A134982 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 %N A134982 Number of elements in the n-th column of Medeleiev's periodic system of elements. %C A134982 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 %C A134982 The corresponding row numbers are A093907; the sum over all a(n) equals 118 in both cases. - _R. J. Mathar_, Feb 08 2008 %C A134982 Comment from _Paul Curtz_, May 03 2008 (Start): %C A134982 1................................................................................................................2 %C A134982 3..4.........................................................................................5...6...7...8...9..10 %C A134982 11.12.......................................................................................13..14..15..16..17..18 %C A134982 19.20.21................................................22..23..24..25..26..27..28..29..30..31..32..33..34..35..36 %C A134982 37.38.39................................................40..41..42..43..44..45..46..47..48..49..50..51..52..53..54 %C A134982 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 %C A134982 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 %C A134982 (End) %Y A134982 Cf. A134984, A093907, A137583, A135559. %K A134982 nonn,fini,full %O A134982 1,1 %A A134982 _Paul Curtz_, Feb 05 2008 %E A134982 Edited by _R. J. Mathar_, Feb 08 2008