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.

A176154 Triangle T(n,k) = Sum_{j=0..k} Stirling1(n, n-j)*binomial(n,j) + Sum_{j=0..n-k} Stirling1(n, n-j)*binomial(n,j), read by rows.

Original entry on oeis.org

2, 2, 2, 0, -2, 0, -1, -10, -10, -1, 20, -4, 86, -4, 20, -78, -128, 102, 102, -128, -78, 77, -13, 1982, -6628, 1982, -13, 77, 2641, 2494, 1129, 12448, 12448, 1129, 2494, 2641, -36944, -37168, 12168, -463496, 745726, -463496, 12168, -37168, -36944
Offset: 0

Views

Author

Roger L. Bagula, Apr 10 2010

Keywords

Examples

			Triangle begins as:
     2;
     2,    2;
     0,   -2,    0;
    -1,  -10,  -10,    -1;
    20,   -4,   86,    -4,    20;
   -78, -128,  102,   102,  -128,  -78;
    77,  -13, 1982, -6628,  1982,  -13,   77;
  2641, 2494, 1129, 12448, 12448, 1129, 2494, 2641;
		

Crossrefs

Programs

  • GAP
    T:= function(n,k) return Sum([0..k], j-> (-1)^j*Stirling1(n,n-j)*Binomial(n,j)) + Sum([0..n-k], j-> (-1)^j*Stirling1(n, n-j)*Binomial(n,j)); end;
    Flat(List([0..10], n-> List([0..n], k-> T(n, k) ))); # G. C. Greubel, Nov 26 2019
  • Magma
    T:= func< n,k | (&+[StirlingFirst(n,n-j)*Binomial(n,j): j in [0..k]]) + (&+[StirlingFirst(n,n-j)*Binomial(n,j): j in [0..n-k]]) >;
    [T(n,k): k in [0..n], n in [0..10]]; // G. C. Greubel, Nov 26 2019
    
  • Maple
    with(combinat);
    T:= proc(n, k) option remember; add(stirling1(n, n-j)*binomial(n, j), j=0..k) + add(stirling1(n, n-j)* binomial(n, j), j=0..n-k); end;
    seq(seq(T(n,k), k=0..n), n=0..10); # G. C. Greubel, Nov 26 2019
  • Mathematica
    T[n_, k_]:= Sum[StirlingS1[n, n-j]*Binomial[n, j], {j, 0, k}] + Sum[StirlingS1[n, n-j]*Binomial[n, j], {j, 0, n-k}];
    Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten
  • PARI
    T(n,k) = sum(j=0,k, stirling(n,n-j,1)*binomial(n,j)) + sum(j=0,n-k, stirling(n, n-j,1)*binomial(n,j)); \\ G. C. Greubel, Nov 26 2019
    
  • Sage
    def T(n, k): return sum((-1)^j*stirling_number1(n,n-j)*binomial(n,j) for j in (0..k)) + sum((-1)^j*stirling_number1(n, n-j)*binomial(n,j) for j in (0..n-k))
    [[T(n, k) for k in (0..n)] for n in (0..10)] # G. C. Greubel, Nov 26 2019
    

Formula

T(n, k) = Sum_{j=0..k} Stirling1(n, n-j)*binomial(n,j) + Sum_{j=0..n-k} Stirling1(n, n-j)*binomial(n,j).

Extensions

Name edited by G. C. Greubel, Nov 27 2019