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 1-2 of 2 results.

A107852 Expansion of -x*(x^2+1)*(x+1)^2/((2*x^3+x^2-1)*(x^4+1)).

Original entry on oeis.org

0, 1, 2, 3, 6, 7, 10, 17, 22, 37, 58, 83, 134, 199, 298, 465, 694, 1061, 1626, 2451, 3750, 5703, 8650, 13201, 20054, 30501, 46458, 70611, 107462, 163527, 248682, 378449, 575734, 875813, 1332634, 2027283, 3084262, 4692551, 7138826, 10861073
Offset: 0

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Author

Creighton Dement, May 25 2005

Keywords

Comments

Floretion Algebra Multiplication Program, FAMP Code: 1baseiforzapseq[(.5i' + .5j' + .5'ki' + .5'kj')*(.5'i + .5'j + .5'ik' + .5'jk')], 1vesforzap = A000004

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[-x(x^2+1)(x+1)^2/((2x^3+x^2-1)(x^4+1)),{x,0, 50}],x] (* or *) LinearRecurrence[ {0,1,2,-1,0,1,2},{0,1,2,3,6,7,10},50] (* Harvey P. Dale, May 03 2024 *)
  • PARI
    a(n)=([0,1,0,0,0,0,0; 0,0,1,0,0,0,0; 0,0,0,1,0,0,0; 0,0,0,0,1,0,0; 0,0,0,0,0,1,0; 0,0,0,0,0,0,1; 2,1,0,-1,2,1,0]^n*[0;1;2;3;6;7;10])[1,1] \\ Charles R Greathouse IV, Oct 03 2016
    
  • PARI
    concat(0, Vec(x*(1 + x)^2*(1 + x^2) / ((1 - x^2 - 2*x^3)*(1 + x^4)) + O(x^45))) \\ Colin Barker, Apr 30 2019

Formula

a(n) = 2*A159284(n) - A091337(n).
a(n) = a(n-2) + 2*a(n-3) - a(n-4) + a(n-6) + 2*a(n-7) for n>6. - Colin Barker, Apr 30 2019

A107854 G.f. x*(x^2+1)*(x^3-x-1)/((2*x^3+x^2-1)*(x^4+1)).

Original entry on oeis.org

0, 1, 1, 2, 3, 3, 5, 8, 11, 19, 29, 42, 67, 99, 149, 232, 347, 531, 813, 1226, 1875, 2851, 4325, 6600, 10027, 15251, 23229, 35306, 53731, 81763, 124341, 189224, 287867, 437907, 666317, 1013642, 1542131, 2346275, 3569413, 5430536, 8261963, 12569363
Offset: 0

Views

Author

Creighton Dement, May 25 2005

Keywords

Comments

The sequence A078028 is given by 1em[I* ]forzapseq and is from the same "batch" (i.e., corresponding to the same floretion and symmetry settings) as A107849, A107850, A107851, A107852, A107853 and (a(n)).
Floretion Algebra Multiplication Program, FAMP Code: 1dia[I]forzapseq[(.5i' + .5j' + .5'ki' + .5'kj')*(.5'i + .5'j + .5'ik' + .5'jk')], 1vesforzap = A000004

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[x(x^2+1)(x^3-x-1)/((2x^3+x^2-1)(x^4+1)),{x,0,50}],x] (* or *) LinearRecurrence[{0,1,2,-1,0,1,2},{0,1,1,2,3,3,5},50] (* Harvey P. Dale, Jun 21 2022 *)
  • PARI
    a(n)=([0,1,0,0,0,0,0; 0,0,1,0,0,0,0; 0,0,0,1,0,0,0; 0,0,0,0,1,0,0; 0,0,0,0,0,1,0; 0,0,0,0,0,0,1; 2,1,0,-1,2,1,0]^n*[0;1;1;2;3;3;5])[1,1] \\ Charles R Greathouse IV, Oct 03 2016

Formula

a(n) = A159284(n) + A014017(n+5).
Showing 1-2 of 2 results.