cp's OEIS Frontend

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.

Showing 1-10 of 11 results. Next

A099956 Atomic numbers of the alkaline earth metals.

Original entry on oeis.org

4, 12, 20, 38, 56, 88
Offset: 1

Views

Author

Parthasarathy Nambi, Nov 12 2004

Keywords

Examples

			12 is the atomic number of magnesium.

Crossrefs

Cf. A099955, alkali metals; A101648, metalloids; A101647, nonmetals (except halogens and noble gases); A097478, halogens; A018227, noble gases; A101649, poor metals.

A138724 Atomic numbers of the periodic table of the elements, read downwards along 18 columns, up to the 7th period.

Original entry on oeis.org

1, 3, 11, 19, 37, 55, 87, 4, 12, 20, 38, 56, 88, 21, 39, 57, 89, 22, 40, 72, 104, 23, 41, 73, 105, 24, 42, 74, 106, 25, 43, 75, 107, 26, 44, 76, 108, 27, 45, 77, 109, 28, 46, 78, 110, 29, 47, 79, 111, 30, 48, 80, 112, 5, 13, 31, 49, 81, 113
Offset: 1

Views

Author

Omar E. Pol, Mar 26 2008, Jan 25 2009

Keywords

Comments

This finite sequence has 90 members. Atomic numbers of the elements of Lanthanide series (58 to 71) and Actinide series (90 to 103) and atomic numbers > 118 are not members.

Examples

			=====================================================================
................. THE PERIODIC TABLE OF THE ELEMENTS ................
=====================================================================
1A 2A 3B .4B .5B .6B .7B .8B .8B .8B .1B .2B .3A .4A .5A .6A .7A .8A
=====================================================================
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 .72 .73 .74 .75 .76 .77 .78 .79 .80 .81 .82 .83 .84 .85 .86
87 88 89 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118
=====================================================================

Crossrefs

Cf. A099955, A134984, A138723, A138725, A138726, A138727.

A101649 Atomic numbers of the poor metals on the periodic table.

Original entry on oeis.org

13, 31, 49, 50, 81, 82, 83
Offset: 1

Views

Author

Robert Happelberg (roberthappelberg(AT)yahoo.com), Dec 10 2004

Keywords

Comments

Elements 113, 114 and 115 are believed to be poor metals too. Element 116 could be either a poor metal or a metalloid. So I'm not putting the keyword full at this time. The poor metals are between the metalloids and the transition metals on the periodic table.

Examples

			The atomic number of aluminium is 13.

References

  • The New Encyclopaedia Britannica, 15th Edition, 1991, Volume 15 (Macropedia), Chemical Elements.

Links

Crossrefs

Cf. A099955, alkali metals; A099956, alkaline earth metals; A101648, metalloids; A101647, nonmetals (except halogens and noble gases); A097478, halogens; A018227, noble gases; A101649, poor metals.

A097478 Atomic numbers of halogens in the periodic table.

Original entry on oeis.org

9, 17, 35, 53, 85, 117
Offset: 1

Views

Author

Parthasarathy Nambi, Sep 19 2004

Keywords

Comments

The halogens are all on the second rightmost column of the periodic table. (The rightmost column belongs to the noble gases.) - Alonso del Arte, Apr 26 2011
Halogens: 9, fluorine (F); 17;,chlorine (Cl); 35, bromine (Br); 53, iodine (I); 85, astatine (At); and 117, tennessine (Ts). - Daniel Forgues, Jul 13 2015, Luca Khan, Sep 09 2024

References

  • Monica Halka and Brian Nordstrom, Halogens and Noble Gases, Facts On File (2010), Part 1: The Halogens.

Links

Crossrefs

Cf. A099955, alkali metals; A099956, alkaline earth metals; A101648, metalloids; A101647, nonmetals (except halogens and noble gases); A018227, noble gases; A101649, poor metals.

Formula

a(1) = 9; a(n) = a(n-1) + 2 * (ceiling(n/2) + 1)^2, 2 <= n <= 6.

A101647 Atomic numbers of elements excluding metals, halogens, and noble gases in the periodic table.

Original entry on oeis.org

1, 6, 7, 8, 15, 16, 34
Offset: 1

Views

Author

Robert Happelberg (roberthappelberg(AT)yahoo.com), Dec 10 2004

Keywords

Comments

"Nonmetals" as normally understood in elementary chemistry.
All nonmetals are sandwiched between the halogens and metalloids on the periodic table, with the exception of hydrogen, which is on the same group as the alkali metals. - Happelberg
There may appear to be some disagreement in regards to the definition of nonmetals. This sequence appears on the cover of the Halka and Nordstrom book on nonmetals, and that book has eight chapters, the first seven of which are each devoted to an element identified by this sequence.
The Baldwin book, on the other hand, flatly declares "All elements to the right of the stepped line [on the periodic table shown in that book] are nonmetals," meaning that the author also considers halogens and noble gases to be nonmetals.
But then there is the Halka and Nordstrom book on halogens and noble gases, which says "The halogens ... are nonmetals, but have such special properties that they are given their own classification. The same is true for the noble gases." - Alonso del Arte, Apr 26 2011

Examples

			Carbon is a nonmetal, and its atomic number is 6.

References

  • Carol Baldwin, Nonmetals. Raintree (2006) p. 13
  • Monica Halka and Brian Nordstrom, Halogens and Noble Gases, Facts On File (2010), p. xiii
  • Monica Halka and Brian Nordstrom, Nonmetals, Facts On File (2010)
  • The New Encyclopaedia Britannica, 15th Edition, 1991, Volume 15 (Macropedia), Chemical Elements.

Links

Crossrefs

Cf. A099955 (alkali metals), A099956 (alkaline earth metals), A101648 (metalloids), A097478 (halogens), A018227 (noble gases), A101649 (poor metals).

A101648 Atomic numbers of the metalloids or semimetals on the periodic table.

Original entry on oeis.org

5, 14, 32, 33, 51, 52, 84
Offset: 1

Views

Author

Robert Happelberg (roberthappelberg(AT)yahoo.com), Dec 10 2004

Keywords

Comments

If ununhexium and ununseptium turn out to be metalloids, 116 and 117 should be added to this sequence, so I'm not putting the keyword full at this time. The metalloids are sandwiched between the nonmetals and the poor metals on the periodic table.

Examples

			The atomic number of boron is 5.

References

  • The New Encyclopaedia Britannica, 15th Edition, 1991, Volume 15 (Macropedia), Chemical Elements.

Links

Crossrefs

Cf. A099955, alkali metals; A099956, alkaline earth metals; A101647, nonmetals (except halogens and noble gases); A097478, halogens; A018227, noble gases; A101649, poor metals.

A138723 Atomic numbers of the periodic table of the elements, read downwards along 18 columns, up to the 5th period.

Original entry on oeis.org

1, 3, 11, 19, 37, 4, 12, 20, 38, 21, 39, 22, 40, 23, 41, 24, 42, 25, 43, 26, 44, 27, 45, 28, 46, 29, 47, 30, 48, 5, 13, 31, 49, 6, 14, 32, 50, 7, 15, 33, 51, 8, 16, 34, 52, 9, 17, 35, 53, 2, 10, 18, 36, 54
Offset: 1

Views

Author

Omar E. Pol, Mar 26 2008, Jan 25 2009

Keywords

Comments

This finite sequence has 54 members. Atomic numbers > 54 are not members.

Examples

			===========================================================
........... THE PERIODIC TABLE OF THE ELEMENTS ............
===========================================================
P/G: 1A 2A 3B 4B 5B 6B 7B 8B 8B 8B 1B 2B 3A 4A 5A 6A 7A 8A
===========================================================
(1): .1 .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .2
(2): .3 .4 .. .. .. .. .. .. .. .. .. .. .5 .6 .7 .8 .9 10
(3): 11 12 .. .. .. .. .. .. .. .. .. .. 13 14 15 16 17 18
(4): 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
(5): 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
===========================================================

Crossrefs

Cf. A099955, A134984, A138724, A138725, A138726, A138727.

A138725 Atomic numbers in the periodic table of the elements, read downwards along 50 columns, up to the 9th period.

Original entry on oeis.org

1, 3, 11, 19, 37, 55, 87, 119, 169, 4, 12, 20, 38, 56, 88, 120, 170, 21, 39, 57, 89, 121, 171, 58, 90, 122, 172, 123, 173, 124, 174, 125, 175, 126, 176, 127, 177, 128, 178, 129, 179, 130, 180, 131, 181, 132, 182, 133, 183, 134, 184
Offset: 1

Views

Author

Omar E. Pol, Mar 26 2008, Jan 25 2009

Keywords

Comments

This finite sequence has 218 members. Atomic numbers > 218 are not members.
This sequence assumes simple extrapolation rather than recent research. - J. Lowell, Jan 26 2021

Examples

			======================================================
................... STRUCTURE OF ....................
........ THE PERIODIC TABLE OF THE ELEMENTS .........
................... (50 columns) ....................
======================================================
1) X................................................X
2) XX..........................................XXXXXX
3) XX..........................................XXXXXX
4) XXX................................XXXXXXXXXXXXXXX
5) XXX................................XXXXXXXXXXXXXXX
6) XXXX..................XXXXXXXXXXXXXXXXXXXXXXXXXXXX
7) XXXX..................XXXXXXXXXXXXXXXXXXXXXXXXXXXX
8) XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
9) XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
======================================================

Crossrefs

Cf. A099955, A134984, A138723, A138724, A138726, A138727.

A138726 Atomic numbers of the periodic table of the elements, read downwards along 72 columns, up to the 11th period.

Original entry on oeis.org

1, 3, 11, 19, 37, 55, 87, 119, 169, 219, 291, 4, 12, 20, 38, 56, 88, 120, 170, 220, 292, 21, 39, 57, 89, 121, 171, 221, 293, 58, 90, 122, 172, 222, 294, 123, 173, 223, 295, 224, 296, 225, 297, 226, 298, 227, 299, 228, 300, 229, 301, 230, 302, 231, 303, 232, 304, 233
Offset: 1

Views

Author

Omar E. Pol, Apr 09 2008

Keywords

Comments

This finite sequence has 362 members. Atomic numbers > 362 are not members.

Examples

			========================================================================
............................ STRUCTURE OF .............................
................. THE PERIODIC TABLE OF THE ELEMENTS ..................
............................ (72 columns) .............................
========================================================================
X......................................................................X
XX................................................................XXXXXX
XX................................................................XXXXXX
XXX......................................................XXXXXXXXXXXXXXX
XXX......................................................XXXXXXXXXXXXXXX
XXXX........................................XXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXX........................................XXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXX......................XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXX......................XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
========================================================================

Crossrefs

Cf. A099955, A134984, A138723, A138724, A138725.

A160914 Extended s-block elements for Janet table.

Original entry on oeis.org

1, 2, 3, 4, 11, 12, 19, 20, 37, 38, 55, 56, 87, 88, 119, 120, 169, 170, 219, 220, 291, 292, 363, 364, 461, 462, 559, 560, 687, 688, 815, 816, 977, 978, 1139, 1140, 1339, 1340, 1539, 1540, 1781, 1782, 2023, 2024, 2311, 2312, 2599, 2600, 2937, 2938, 3275, 3276
Offset: 1

Views

Author

Paul Curtz, Oct 15 2011

Keywords

Comments

See A168342. Must be included in A167268. From right to left, first vertical is A168380 from 1 to 8. Second vertical is A168380-1. In (1) page 12, introducing elements 93 to 120, Janet says that there is a probable 8th row. For row 8, he proposes, like for row 7, 32 elements (89 to 120). Page 16 he presents 4 blocks: first has 2*8 elements, second: 6*6, third: 10*4, fourth: 14*2. Today, blocks are s,p,d,f for Mendeleyev-Moseley-Seaborg 118 elements periodic table. See (2), (3), A173592 and A138509. In 1927, only 88 on the first 92 elements were known; 41 (1937 discovered), 61 (1947), 85 (1940) and 87 (1939) were missing. Since 2010 (117 discovered) the first 118 elements are known. Janet predicted only 120 elements.

Examples

			The following is an s-block, 2*8=16 elements, i.e., a(n) written vertically, after p-block, 6*6, (A138469).
                          1   2
                          3   4
5   6   7   8   9   10   11  12
13  14  15  16  17  18   19  20
31  32  33  34  35  36   37  38
49  50  51  52  53  54   55  56
81  82  83  84  85  86   87  88
113 114 115 116 117 118  119 120

References

  • Charles JANET, La structure du Noyau de l'atome,considérée dans la Classification périodique, des éléments chimiques, 1927 (Novembre) N. 2 Beauvais, 67 pages, 3 leaflets.

Crossrefs

Cf. A099955.
Showing 1-10 of 11 results. Next

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