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.

A062707 Table by antidiagonals of n*k*(k+1)/2.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 3, 2, 0, 0, 6, 6, 3, 0, 0, 10, 12, 9, 4, 0, 0, 15, 20, 18, 12, 5, 0, 0, 21, 30, 30, 24, 15, 6, 0, 0, 28, 42, 45, 40, 30, 18, 7, 0, 0, 36, 56, 63, 60, 50, 36, 21, 8, 0, 0, 45, 72, 84, 84, 75, 60, 42, 24, 9, 0, 0, 55, 90, 108, 112, 105, 90, 70, 48, 27, 10, 0
Offset: 0

Views

Author

Henry Bottomley, Jul 11 2001

Keywords

Examples

			  0   0   0   0   0   0   0   0   0
  0   1   3   6  10  15  21  28  36
  0   2   6  12  20  30  42  56  72
  0   3   9  18  30  45  63  84 108
  0   4  12  24  40  60  84 112 144
  0   5  15  30  50  75 105 140 180
  0   6  18  36  60  90 126 168 216
  0   7  21  42  70 105 147 196 252
  0   8  24  48  80 120 168 224 288
		

Crossrefs

Main diagonal is A002411. Sum of antidiagonals is A000332.

Programs

  • GAP
    Flat(List([0..12], n-> List([0..n], k-> k*Binomial(n-k+1,2)))); # G. C. Greubel, Sep 02 2019
  • Magma
    [k*Binomial(n-k+1,2): k in [0..n], n in [0..12]]; // G. C. Greubel, Sep 02 2019
    
  • Maple
    seq(seq(k*binomial(n-k+1,2), k=0..n), n=0..12); # G. C. Greubel, Sep 02 2019
  • Mathematica
    Table[k*Binomial[n-k+1, 2], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Sep 02 2019 *)
  • PARI
    T(n,k) = k*binomial(n-k+1,2);
    for(n=0,12, for(k=0,n, print1(T(n,k), ", "))) \\ G. C. Greubel, Sep 02 2019
    
  • Sage
    [[k*binomial(n-k+1,2) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Sep 02 2019
    

Formula

T(n, k) = T(n, 1)*T(1, k) = A001477(n)*A000217(k).
T(n, k) = A057145(n+2, k+1)-(k+1).