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 1-4 of 4 results.

A134888 E_8 numbers: a(n) = 2^(2*n) * 3^(3*n) * 5^n * 839^n. (Constants are prime numbers).

Original entry on oeis.org

1, 453060, 205263363600, 92996619512616000, 42133048436385804960000, 19088798924588952795177600000, 8648371240774270953383163456000000, 3918231074345191198139776035375360000000, 1775193770542832324229206930587160601600000000
Offset: 0

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Author

Omar E. Pol, Nov 22 2007

Keywords

Comments

The result of the exceptional Lie group E_8 calculation is a matrix with 453060 rows and columns. Size of the matrix = a(1) = 453060. Number of entries = a(2) = 205263363600.

Examples

			a(1) = 453060 because 2^(2*1)=4, 3^(3*1)=27, 5^1=5, 839^1=839 and we can write 4*27*5*839 = 453060.
a(2) = 205263363600 because 2^(2*2)=16, 3^(3*2)=729, 5^2=25, 839^2=703921 and we can write 16*729*25*703921=205263363600.
a(1)^2 = a(2): 453060*453060 = 205263363600.
		

Crossrefs

Programs

  • Mathematica
    NestList[453060*# &, 1, 10] (* Paolo Xausa, Jul 14 2025 *)

Formula

a(n) = 2^(2*n) * 3^(3*n) * 5^n * 839^n.
O.g.f.: 1/(1-453060*x). - R. J. Mathar, Nov 24 2007
a(n) = 453060^n.
From Elmo R. Oliveira, Jul 05 2025: (Start)
E.g.f.: exp(453060*x).
a(n) = 453060*a(n-1).
a(n) = 540^n * A135640(n). (End)

Extensions

Terms a(5) and beyond from Andrew Howroyd, Feb 02 2020

A135639 a(n) = 839*n.

Original entry on oeis.org

0, 839, 1678, 2517, 3356, 4195, 5034, 5873, 6712, 7551, 8390, 9229, 10068, 10907, 11746, 12585, 13424, 14263, 15102, 15941, 16780, 17619, 18458, 19297, 20136, 20975, 21814, 22653, 23492, 24331, 25170, 26009, 26848, 27687, 28526
Offset: 0

Views

Author

Omar E. Pol, Nov 27 2007

Keywords

Comments

The 146th prime number (839) and some of its multiples are related to the exceptional Lie group E_8 calculation because the result is a matrix with 453060 rows and columns. The size of the matrix is the member a(540)=453060 of this sequence. The number 839 is the largest prime factor of 453060 because we can write 2*2*3*3*3*5*839=453060. The number of entries of the matrix is the member a(244652400)=453060*453060=205263363600.

Examples

			a(1)=839. a(540)=540*839=453060. a(244652400)=244652400*839=205263363600.
		

Crossrefs

Programs

Formula

From G. C. Greubel, Oct 25 2016: (Start)
a(n) = 2*a(n-1) - a(n-2).
G.f.: (839*x)/(1 - x)^2.
E.g.f.: 839*x*exp(x). (End)

A134960 a(n) = n*453060.

Original entry on oeis.org

0, 453060, 906120, 1359180, 1812240, 2265300, 2718360, 3171420, 3624480, 4077540, 4530600, 4983660, 5436720, 5889780, 6342840, 6795900, 7248960, 7702020, 8155080, 8608140, 9061200, 9514260, 9967320, 10420380, 10873440, 11326500, 11779560, 12232620, 12685680, 13138740
Offset: 0

Views

Author

Omar E. Pol, Nov 27 2007

Keywords

Comments

The first positive member of this sequence and some of its multiples are related to the exceptional Lie group E_8 calculation. The result of the calculation is a matrix with 453060 rows and columns. The size of the matrix is a(1)=453060 and the number of entries of the matrix is a(453060)=453060*453060=205263363600.

Examples

			a(1) = 453060. a(453060) = 453060*453060 = 205263363600.
		

Crossrefs

Programs

Formula

From Elmo R. Oliveira, Jul 05 2025: (Start)
G.f.: 453060*x/(1-x)^2.
E.g.f.: 453060*x*exp(x).
a(n) = 540*A135639(n).
a(n) = 2*a(n-1) - a(n-2). (End)

Extensions

More terms from Elmo R. Oliveira, Jul 05 2025

A018509 Divisors of 540.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 27, 30, 36, 45, 54, 60, 90, 108, 135, 180, 270, 540
Offset: 1

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Author

Keywords

Crossrefs

Cf. A134950.

Programs

Showing 1-4 of 4 results.