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.

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A165412 Divisors of 2520.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 18, 20, 21, 24, 28, 30, 35, 36, 40, 42, 45, 56, 60, 63, 70, 72, 84, 90, 105, 120, 126, 140, 168, 180, 210, 252, 280, 315, 360, 420, 504, 630, 840, 1260, 2520
Offset: 1

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Author

Reinhard Zumkeller, Sep 17 2009

Keywords

Comments

2520 is the largest and last of most highly composite numbers = A072938(7) = A002182(18) = 2520;
a(A000005(2520)) = a(48) = 2520 is the last term.
A242627(2520*n) = 9. - Reinhard Zumkeller, Jul 16 2014

Links

Crossrefs

Cf. A018336, A018357, A018388, A018412, A018444, A018490, A018559, and A018676 are subsets.
Cf. A018253, A018256, A018261, A018266, A018293, A018321, A018350, A018609, A178877, A178878, A178858, A178859, A178860, A178861, A178862, A178863, A178864.

Programs

A178864 Divisors of 27720.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 18, 20, 21, 22, 24, 28, 30, 33, 35, 36, 40, 42, 44, 45, 55, 56, 60, 63, 66, 70, 72, 77, 84, 88, 90, 99, 105, 110, 120, 126, 132, 140, 154, 165, 168, 180, 198, 210, 220, 231, 252, 264, 280, 308, 315, 330, 360, 385, 396, 420
Offset: 1

Views

Author

Reinhard Zumkeller, Jun 21 2010

Keywords

Comments

27720 is a highly composite number: A002182(25)=27720;
the sequence is finite with A002183(25)=96 terms: a(96)=27720.

Links

Crossrefs

Cf. A018253, A018256, A018261, A018266, A018293, A018321, A018350, A018412, A018609, A018676, A178877, A178878, A165412, A178858, A178859, A178860, A178861, A178862, A178863.

Programs

A018293 Divisors of 120.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Comments

120 is a highly composite number: A002182(10) = 120. - Reinhard Zumkeller, Jun 21 2010
120 is the first 3-perfect number: A005820(1) = 120. - Michel Marcus, Nov 21 2015
There are 279 ways to partition 120 as a sum of its distinct divisors (see A033630). This is more than any smaller number (hence 120 is listed in A065218). - Alonso del Arte, Oct 12 2017

Links

Crossrefs

Cf. A018253, A018256, A018261, A018266, A018321, A018350, A018412, A018609, A018676, A178877, A178878, A165412, A178858, A178859, A178860, A178861, A178862, A178863, A178864. - Reinhard Zumkeller, Jun 21 2010

Programs

A018321 Divisors of 180.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 60, 90, 180
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Comments

These divisors represent a special case of the "nice angles" discussed at the Geometry Center when bending generating triangles to construct polyhedra (link given below). - Alford Arnold, Apr 16 2000
180 is a highly composite number: A002182(11) = 180. - Reinhard Zumkeller, Jun 21 2010
There are 752 ways to partition 180 as a sum of some of its distinct divisors (see A033630). This is more than any smaller number (hence 180 is listed in A065218). - Alonso del Arte, Sep 20 2017

Links

Crossrefs

Cf. A018253, A018256, A018261, A018266, A018293, A018412, A018350, A018609, A018676, A178877, A178878, A165412, A178858, A178859, A178860, A178861, A178862, A178863, A178864.

Programs

A018350 Divisors of 240.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, 120, 240
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Comments

240 is a highly composite number: A002182(12) = 240. - Reinhard Zumkeller, Jun 21 2010
There are 2158 ways to partition 240 as a sum of some of its distinct divisors (see A033630). This is more than any smaller number (hence 240 is listed in A065218). - Alonso del Arte, Dec 20 2017

Links

Crossrefs

Cf. A018253, A018256, A018261, A018266, A018293, A018321, A018412, A018609, A018676, A178877, A178878, A165412, A178858, A178859, A178860, A178861, A178862, A178863, A178864.

Programs

A018676 Divisors of 840.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 70, 84, 105, 120, 140, 168, 210, 280, 420, 840
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Comments

840 is a highly composite number: A002182(15)=840. - Reinhard Zumkeller, Jun 21 2010

Links

Crossrefs

Cf. A018253, A018256, A018261, A018266, A018293, A018321, A018350, A018412, A018609, A178877, A178878, A165412, A178858, A178859, A178860, A178861, A178862, A178863, A178864.

Programs

A160811 Numbers not dividing 24.

Original entry on oeis.org

5, 7, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 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
Offset: 1

Views

Author

Omar E. Pol, Jun 19 2009, Jun 28 2009

Keywords

Comments

These terms m > 5 can be called "triphile" or "3-phile" numbers, because there are 3 positive integers b_1 < b_2 < b_3 such that b_1 divides b_2, b_2 divides b_3 and m = b_1 + b_2 + b_3. A number that is not "triphile" is called "triphobe" or "3-phobe" (A019532). The smallest triphile number is 7 = 1 + 2 + 4 and the largest triphobe is 24. See A348517 for more explanations and link. - Bernard Schott, Oct 21 2021

Links

Crossrefs

Complement of A018253.
Cf. A000005, A000720, A161205.
Cf. A019532, A348517.

Programs

Formula

a(n) = n + 8 for n > 16. [Charles R Greathouse IV, Oct 26 2011]

Extensions

Definition corrected by Omar E. Pol, Nov 17 2009

A178858 Divisors of 5040.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 24, 28, 30, 35, 36, 40, 42, 45, 48, 56, 60, 63, 70, 72, 80, 84, 90, 105, 112, 120, 126, 140, 144, 168, 180, 210, 240, 252, 280, 315, 336, 360, 420, 504, 560, 630, 720, 840, 1008, 1260, 1680, 2520, 5040
Offset: 1

Views

Author

Reinhard Zumkeller, Jun 21 2010

Keywords

Comments

5040 is a highly composite number: A002182(19)=5040;
the sequence is finite with A002183(19)=60 terms: a(60)=5040.

Links

Crossrefs

Cf. A018253, A018256, A018261, A018266, A018293, A018321, A018350, A018412, A018609, A018676, A178877, A178878, A165412, A178859, A178860, A178861, A178862, A178863, A178864.

Programs

A178859 Divisors of 7560.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 18, 20, 21, 24, 27, 28, 30, 35, 36, 40, 42, 45, 54, 56, 60, 63, 70, 72, 84, 90, 105, 108, 120, 126, 135, 140, 168, 180, 189, 210, 216, 252, 270, 280, 315, 360, 378, 420, 504, 540, 630, 756, 840, 945, 1080, 1260, 1512, 1890
Offset: 1

Views

Author

Reinhard Zumkeller, Jun 21 2010

Keywords

Comments

7560 is a highly composite number: A002182(20)=7560.
The sequence is finite with A002183(20)=64 terms: a(64)=7560.
Its primorial factorization is 6^2 * 210 and its representing polynomial p(x) of degree 6 with x=2 is x^6 + 18x^5 + 118x^4 + 348x^3 + 457x^2 + 210x. - Carlos Eduardo Olivieri, May 02 2015

Links

Crossrefs

Cf. A018253, A018256, A018261, A018266, A018293, A018321, A018350, A018412, A018609, A018676, A178877, A178878, A165412, A178858, A178860, A178861, A178862, A178863, A178864.

Programs

A178860 Divisors of 10080.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 24, 28, 30, 32, 35, 36, 40, 42, 45, 48, 56, 60, 63, 70, 72, 80, 84, 90, 96, 105, 112, 120, 126, 140, 144, 160, 168, 180, 210, 224, 240, 252, 280, 288, 315, 336, 360, 420, 480, 504, 560, 630, 672, 720, 840, 1008
Offset: 1

Views

Author

Reinhard Zumkeller, Jun 21 2010

Keywords

Comments

10080 is a highly composite number: A002182(21)=10080.
The sequence is finite with A002183(21)=72 terms: a(72)=10080.

Links

Crossrefs

Cf. A018253, A018256, A018261, A018266, A018293, A018321, A018350, A018412, A018609, A018676, A178877, A178878, A165412, A178858, A178859, A178861, A178862, A178863, A178864.

Programs

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Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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