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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A110653 n^2 followed by n^3 followed by n followed by n^4.

Original entry on oeis.org

1, 1, 1, 1, 4, 8, 2, 16, 9, 27, 3, 81, 16, 64, 4, 256, 25, 125, 5, 625, 36, 216, 6, 1296, 49, 343, 7, 2401, 64, 512, 8, 4096, 81, 729, 9, 6561, 100, 1000, 10, 10000, 121, 1331, 11, 14641, 144, 1728, 12, 20736, 169, 2197, 13, 28561, 196, 2744, 14, 38416, 225, 3375
Offset: 1

Views

Author

Mohammad K. Azarian, Sep 14 2005

Keywords

Crossrefs

Programs

  • Magma
    &cat[[n^2, n^3, n, n^4]: n in [1..20]]; // Vincenzo Librandi, Feb 06 2013
  • Mathematica
    Flatten[Table[{n^2, n^3, n, n^4}, {n, 40}]] (* Vincenzo Librandi, Feb 06 2013 *)

Formula

a(n) = floor((n+3)/4)^((-2*(n mod 4)^3+9*(n mod 4)^2 - 11*(n mod 4) + 8)/2). - Luce ETIENNE, Apr 07 2018
From Chai Wah Wu, Jan 11 2020: (Start)
a(n) = 5*a(n-4) - 10*a(n-8) + 10*a(n-12) - 5*a(n-16) + a(n-20) for n > 20.
G.f.: x*(-x^15 + x^14 + x^13 - x^12 - 11*x^11 - 3*x^10 + 3*x^9 + x^8 - 11*x^7 + 3*x^6 - 3*x^5 + x^4 - x^3 - x^2 - x - 1)/((x - 1)^5*(x + 1)^5*(x^2 + 1)^5). (End)

A110005 n followed by n^2 followed by n^4 followed by n^3.

Original entry on oeis.org

1, 1, 1, 1, 2, 4, 16, 8, 3, 9, 81, 27, 4, 16, 256, 64, 5, 25, 625, 125, 6, 36, 1296, 216, 7, 49, 2401, 343, 8, 64, 4096, 512, 9, 81, 6561, 729, 10, 100, 10000, 1000, 11, 121, 14641, 1331, 12, 144, 20736, 1728, 13, 169, 28561, 2197, 14, 196, 38416, 2744, 15, 225
Offset: 1

Views

Author

Mohammad K. Azarian, Sep 02 2005

Keywords

Crossrefs

Programs

  • Mathematica
    Table[{n,n^2,n^4,n^3},{n,20}]//Flatten (* Harvey P. Dale, Jan 12 2020 *)

Formula

G.f.: x*(-1 -x -x^2 -x^3 +3*x^4 +x^5 -11*x^6 -3*x^7 -3*x^8 +x^9 -11*x^10 +3*x^11 +x^12 -x^13 -x^14 +x^15) / ( (x-1)^5 *(1+x)^5 *(x^2+1)^5 ). - R. J. Mathar, Sep 10 2016
a(n) = floor((n+3)/4)^((-2*(n mod 4)^3 + 15*(n mod 4)^2 -25*(n mod 4) +18)/6). - Luce ETIENNE, Apr 07 2018

A126951 List of pairs: k followed by k^3.

Original entry on oeis.org

1, 1, 2, 8, 3, 27, 4, 64, 5, 125, 6, 216, 7, 343, 8, 512, 9, 729, 10, 1000, 11, 1331, 12, 1728, 13, 2197, 14, 2744, 15, 3375, 16, 4096, 17, 4913, 18, 5832, 19, 6859, 20, 8000, 21, 9261, 22, 10648, 23, 12167, 24, 13824, 25, 15625, 26, 17576, 27, 19683, 28, 21952
Offset: 1

Views

Author

Zak Seidov, Mar 18 2007

Keywords

Crossrefs

Programs

  • Magma
    &cat[ [ n, n^3 ]: n in [1..40] ]; // Vincenzo Librandi, Apr 21 2011
  • Mathematica
    Table[((((-1)^(n+1))+1)/4)(n+1)- ((((-1)^(n+1))-1)/16)n^3,{n,64}]
    Flatten[Table[{n,n^3},{n,30}]] (* or *) LinearRecurrence[{0,4,0,-6,0,4,0,-1},{1,1,2,8,3,27,4,64},60] (* Harvey P. Dale, Mar 11 2018 *)

Formula

a(n) = (n+1)/2 if n is odd, a(n) = (n/2)^3 otherwise;
a(n) = ((((-1)^(n+1))+1)/4)*(n+1) - ((((-1)^(n+1))-1)/16)*n^3;
g.f.: (x + x^2 - 2*x^3 + 4*x^4 + x^5 + x^6)/(1 - x^2)^4.
Previous Showing 11-13 of 13 results.