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 1-5 of 5 results.

A127228 a(n) = numerator of ((n + 4)! - (n - 4)!)/(n!).

Original entry on oeis.org

40319, 362879, 1814399, 6652799, 19958399, 51891839, 121080959, 259459199, 518918399, 980179199, 1764322559, 3047466239, 5079110399, 8204716799, 12893126399, 19769460479, 29654190719, 43609103999, 62990927999
Offset: 4

Views

Author

Artur Jasinski, Jan 09 2007

Keywords

Crossrefs

Programs

  • Maple
    f::= n -> (n+4)*(n+3)*(n+2)*(n+1)*n*(n-1)*(n-2)*(n-3)-1:
    map(f, [$4..30]); # Robert Israel, Nov 20 2023
  • Mathematica
    Table[Numerator[((n + 4)! - (n - 4)!)/(n!)], {n, 4, 30}]

Formula

a(n) = (n+4) * (n+3) * (n+2) * (n+1) * n * (n-1) * (n-2) * (n-3) - 1. - Robert Israel, Nov 20 2023

A127229 a(n)= numerator of ((n + 5)! - (n - 5)!)/(n!).

Original entry on oeis.org

3628799, 39916799, 239500799, 1037836799, 3632428799, 10897286399, 29059430399, 70572902399, 158789030399, 335221286399, 670442572799, 1279935820799, 2346549004799, 4151586700799, 7117005772799, 11861676287999, 19275223967999, 30613591007999, 47621141567999
Offset: 5

Views

Author

Artur Jasinski, Jan 09 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Numerator[((n + 5)! - (n - 5)!)/(n!)], {n, 5, 30}]

A127227 a(n)= numerator of ((n + 3)! - (n - 3)!)/(n!).

Original entry on oeis.org

719, 5039, 20159, 60479, 151199, 332639, 665279, 1235519, 2162159, 3603599, 5765759, 8910719, 13366079, 19535039, 27907199, 39070079, 53721359, 72681839, 96909119, 127511999, 165765599, 213127199, 271252799, 342014399, 427517999
Offset: 3

Views

Author

Artur Jasinski, Jan 09 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Numerator[((n + 3)! - (n - 3)!)/(n!)], {n, 3, 30}]

A127231 a(n) = (2n)! + 1.

Original entry on oeis.org

2, 3, 25, 721, 40321, 3628801, 479001601, 87178291201, 20922789888001, 6402373705728001, 2432902008176640001, 1124000727777607680001, 620448401733239439360001, 403291461126605635584000001, 304888344611713860501504000001, 265252859812191058636308480000001
Offset: 0

Views

Author

Artur Jasinski, Jan 09 2007

Keywords

Crossrefs

Programs

Extensions

Entry revised by N. J. A. Sloane, Mar 26 2021

A013325 Numerator of [x^n] in the Taylor series arccosh(exp(x)-arctanh(x))= x-x^2/6-x^3/72 -359*x^4/2160 -1681*x^5/51840 -52981*x^6/435456 -...

Original entry on oeis.org

1, -1, -1, -359, -1681, -52981, -1887113, -27492467, -3259141, -1194145112779, -55919619312049, -7462251938940527, -113201511292945547, -1055956853774285077, -44032898634010565651, -75833822693358307239889
Offset: 1

Views

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Keywords

Comments

The inner function exp(x)-arctanh(x) = 1+x^2/2! -x^3/3! +x^4/4! -23*x^5/120 + x^6/6! -719*x^7/7!.. has e.g.f. coefficients apparently closely related to A127230.

Extensions

Values replaced by numerators. - R. J. Mathar, Dec 22 2011
Showing 1-5 of 5 results.