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 1-7 of 7 results.

A137937 A137904(n) - A137575(n).

Original entry on oeis.org

0, 0, 3, 4, 5, 6, 7, 8, 9, 10, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 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
Offset: 0

Views

Author

Paul Curtz, Apr 30 2008

Keywords

Comments

To have 0 upon vertical 2, 10, 18, 36, 54, 86 (noble gases) is not a problem (with the help of A137583. A (second) 0 upon 1, 3, 11, 19, 37, 55, 87 (alkali metals), seems paradoxal. Is 120 terms (elements) sequence 0, 0, 1, 2, .. 117, 118 credible? This leads to a row 0 (0 upon hydrogen, 0 upon helium). Two common points with Janet periodic table elements.
60 terms: another, with A137913, theoritical companion to A137904.

Crossrefs

Cf. A134984, A137575, A137904.

Formula

A137913 prepended with 0, 0.

A137583 Number of elements in the n-th period of the Janet periodic table of elements.

Original entry on oeis.org

2, 2, 8, 8, 18, 18, 32, 32
Offset: 1

Views

Author

Paul Curtz, Apr 26 2008

Keywords

Comments

Essentially 2 followed by the first terms of A093907.
This puts Hydrogen and Helium in the first row, Lithium and Beryllium into the second, Boron to Magnesium into the third etc.

Links

Crossrefs

Cf. A093907, A137508, A138509, A137575.

Programs

  • Mathematica
    Flatten@ Table[2 (n #)^2 & /@ {-1, 1}, {n, 4}] (* Michael De Vlieger, Jul 22 2016 *)

Extensions

Edited by R. J. Mathar, Oct 02 2009

A138102 The number 2*k^2 repeated 2*k^2 times, k=1 to 4.

Original entry on oeis.org

2, 2, 8, 8, 8, 8, 8, 8, 8, 8, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32
Offset: 1

Views

Author

Paul Curtz, May 03 2008

Keywords

Comments

Vaguely related to the number of elements in the Janet table A138102.
Essentially the same as A137575.
a(n)= (A138101=3,4,13,14,15,16,17,) - (A138100=1,2,5,6,7,8,9,) . [From Paul Curtz, Oct 11 2009]

Links

Crossrefs

Cf. A138101, A137325, A137583, A166071, A001105.

Extensions

Edited by R. J. Mathar, Oct 07 2009

A137904 Rows 1, 3, 5, 7 of Mendeleyev-Seaborg (extended to 32 columns) periodic table elements.

Original entry on oeis.org

1, 2, 11, 12, 13, 14, 15, 16, 17, 18, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 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
Offset: 0

Views

Author

Paul Curtz, Apr 30 2008

Keywords

Comments

60 terms. See A137575 (58 terms for rows 2, 4, 6). Differences 9, 19, 33 leads to difference 3 before a(1)=1. Hence -2, antihelium. Like A137583, 2, 2, 8 for A018227, 2, 10, 18, "magic numbers".

References

  • R. Arsenescu, Antihelium-3 production in lead-lead collisions at 158 A GeV/c. New Journal of Physics 5:1,2003. doi:10.1088/1367-2630/5/1/301.

Crossrefs

Cf. A134984, A137913.

A138040 Atomic number of the 2nd transition metal (group 4) in the n-th row of the periodic system of elements.

Original entry on oeis.org

22, 40, 72, 104
Offset: 4

Views

Author

Paul Curtz, May 02 2008

Keywords

Comments

Refers to Titanium=22, Zirconium=40, Hafnium=72, Rutherfordium=104.

Links

Crossrefs

Cf. A134984, A138724, A137575.

Extensions

Edited by R. J. Mathar, May 21 2009

A138052 Atomic number of the penultimate transition metal (group 11) in the n-th row of the periodic system of elements.

Original entry on oeis.org

29, 47, 79, 111
Offset: 4

Views

Author

Paul Curtz, May 02 2008

Keywords

Comments

This refers to Cu=29, Ar=47, Au=79, and Rg=111.
The first differences are 18, 18, 32, indicating that there is a row of Lanthanides between Au and Rg.

Links

Crossrefs

Cf. A134984, A138724, A137575, A137846, A138040.

Extensions

Edited by R. J. Mathar, May 21 2009

A138300 Differences of each column for atomic numbers of Mendeleyev-Seaborg 7*32 elements periodic table,first extension,A138096 table.86 terms.Horizontal lecture.

Original entry on oeis.org

2, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32
Offset: 0

Views

Author

Paul Curtz, May 07 2008

Keywords

Examples

			First column differences: 2, 8, 8, 18, 18, 32; second: 8, 8, 18, 18, 32.
Table: 1 2, 11 8's, 27 18's, 47 32's
2.............................................................................................8
8..8...........................................................................8..8..8..8..8..8
8..8..........................................................................18.18.18.18.18.18
18.18.18...........................................18.18.18.18.18.18.18.18.18.18.18.18.18.18.18
18.18.18...........................................32.32.32.32.32.32.32.32.32.32.32.32.32.32.32
32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32.32

Crossrefs

Cf. A093907, A137508, A137575, A137583, A138102.
Showing 1-7 of 7 results.

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