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.

A104793 Triangle T(n,k) = A023537(n-k), n >= 1, 0 <= k < n, read by rows.

Original entry on oeis.org

1, 5, 1, 13, 5, 1, 28, 13, 5, 1, 54, 28, 13, 5, 1, 98, 54, 28, 13, 5, 1, 171, 98, 54, 28, 13, 5, 1, 291, 171, 98, 54, 28, 13, 5, 1, 487, 291, 171, 98, 54, 28, 13, 5, 1, 806, 487, 291, 171, 98, 54, 28, 13, 5, 1, 1324, 806, 487, 291, 171, 98, 54, 28, 13, 5, 1
Offset: 1

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Author

Gary W. Adamson, Mar 26 2005

Keywords

Comments

Repeatedly writing the sequence A023537 backwards.

Examples

			First few rows of the triangle are:
   1;
   5,  1;
  13,  5,  1;
  28, 13,  5,  1;
  54, 28, 13,  5, 1;
  98, 54, 28, 13, 5, 1; ...
		

Crossrefs

Row sums are in A027963.
Cf. A104765.

Programs

  • GAP
    Flat(List([1..12], n-> List([0..n-1], k-> Lucas(1, -1, n-k+4)[2] -3*n+3*k-7 ))); # G. C. Greubel, Jun 01 2019
  • Magma
    [[Lucas(n-k+4) -(3*n-3*k+7): k in [0..n-1]]: n in [1..12]]; // G. C. Greubel, Jun 01 2019
    
  • Mathematica
    Table[LucasL[n-k+4] -3*n+3*k-7, {n,1,12}, {k,0,n-1}]//Flatten (* G. C. Greubel, Jun 01 2019 *)
  • PARI
    {T(n,k) = fibonacci(n-k+5) + fibonacci(n-k+3) -3*n +3*k - 7}; \\ G. C. Greubel, Jun 01 2019
    
  • Sage
    [[lucas_number2(n-k+4, 1, -1) -3*n+3*k-7 for k in (0..n-1)] for n in (1..12)] # G. C. Greubel, Jun 01 2019
    

Formula

From Ralf Stephan, Apr 05 2009: (Start)
T(n,k) = Lucas(n-k+4) - (3*n - 3*k + 7).
T(n,k) = A023537(A004736(n, k+1)). (End)

Extensions

Edited by Ralf Stephan, Apr 05 2009