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.

A122753 Triangle of coefficients of (1 - x)^n*B_n(x/(1 - x)), where B_n(x) is the n-th Bell polynomial.

Original entry on oeis.org

1, 0, 1, 0, 1, 0, 1, 1, -1, 0, 1, 4, -5, 1, 0, 1, 11, -14, 1, 2, 0, 1, 26, -24, -29, 36, -9, 0, 1, 57, 1, -244, 281, -104, 9, 0, 1, 120, 225, -1259, 1401, -454, -83, 50, 0, 1, 247, 1268, -5081, 4621, 911, -3422, 1723, -267, 0, 1, 502, 5278, -16981, 5335, 30871
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Sep 21 2006

Keywords

Comments

The n-th row consists of the coefficients in the expansion of Sum_{j=0..n} A048993(n,j)*x^j*(1 - x)^(n - j), where A048993 is the triangle of Stirling numbers of second kind.

Examples

			Triangle begins:
    1;
    0, 1;
    0, 1;
    0, 1,   1,   -1;
    0, 1,   4,   -5,     1;
    0, 1,  11,  -14,     1,    2;
    0, 1,  26,  -24,   -29,   36,   -9;
    0, 1,  57,    1,  -244,  281, -104,     9;
    0, 1, 120,  225, -1259, 1401, -454,   -83,   50;
    0, 1, 247, 1268, -5081, 4621,  911, -3422, 1723, -267;
    ... reformatted and extended. - _Franck Maminirina Ramaharo_, Oct 10 2018
		

References

  • M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, pp. 824-825.

Crossrefs

Programs

  • Mathematica
    Table[CoefficientList[Sum[StirlingS2[m, n]*x^n*(1-x)^(m-n), {n,0,m}], x], {m,0,10}]//Flatten
  • Maxima
    P(x, n) := expand(sum(stirling2(n, j)*x^j*(1 - x)^(n - j), j, 0, n))$
    T(n, k) := ratcoef(P(x, n), x, k)$
    tabf(nn) := for n:0 thru nn do print(makelist(T(n, k), k, 0, hipow(P(x, n), x)))$ /* Franck Maminirina Ramaharo, Oct 10 2018 */
    
  • Sage
    def p(n,x): return sum( stirling_number2(n, j)*x^j*(1-x)^(n-j) for j in (0..n) )
    def T(n): return ( p(n,x) ).full_simplify().coefficients(sparse=False)
    flatten([T(n) for n in (0..12)]) # G. C. Greubel, Jul 15 2021

Formula

From Franck Maminirina Ramaharo, Oct 10 2018: (Start)
E.g.f.: exp((x/(1 - x))*(exp((1 - x)*y) - 1)).
T(n,1) = A000295(n-1). (End)

Extensions

Edited, new name, and offset corrected by Franck Maminirina Ramaharo, Oct 10 2018

A142070 Triangle T(n,k) read by rows: the coefficient [x^k] of the polynomial Product_{i=1..n} (i+1)*x-i in row n>=0 and column 0<=k<=n.

Original entry on oeis.org

1, -1, 2, 2, -7, 6, -6, 29, -46, 24, 24, -146, 329, -326, 120, -120, 874, -2521, 3604, -2556, 720, 720, -6084, 21244, -39271, 40564, -22212, 5040, -5040, 48348, -197380, 444849, -598116, 479996, -212976, 40320, 40320, -432144, 2014172, -5335212, 8788569, -9223012, 6023772, -2239344, 362880
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Sep 15 2008

Keywords

Comments

This is essentially a signed version of A088996. - Peter Bala, Jan 09 2017

Examples

			Triangle begins as:
      1;
     -1,       2;
      2,      -7,       6;
     -6,      29,     -46,       24;
     24,    -146,     329,     -326,     120;
   -120,     874,   -2521,     3604,   -2556,      720;
    720,   -6084,   21244,   -39271,   40564,   -22212,    5040;
  -5040,   48348, -197380,   444849, -598116,   479996, -212976,    40320;
  40320, -432144, 2014172, -5335212, 8788569, -9223012, 6023772, -2239344, 362880;
		

Crossrefs

Programs

  • Magma
    A142070:= func< n,k | (-1)^(n-k)*(&+[(-1)^j*Binomial(j,n-k)*StirlingFirst(n+1,n-j+1): j in [0..n]]) >;
    [A142070(n,k): k in [0..n], n in [0..10]]; // G. C. Greubel, Feb 24 2022
    
  • Maple
    A142070 := proc(n,k)
        local x,i ;
        mul( (i+1)*x-i,i=1..n) ;
        expand(%) ;
        coeff(%,x,k) ;
    end proc:
  • Mathematica
    (* First program *)
    p[x_, n_]:= Product[(i+1)*x - i, {i, n}];
    Table[CoefficientList[p[x, n], x], {n,0,10}]//Flatten
    (* Second program *)
    T[n_, k_]:= T[n, k]= Sum[(-1)^j*Binomial[j+n-k, n-k]*StirlingS1[n+1,k-j+1], {j, 0, k}];
    Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten (* G. C. Greubel, Feb 24 2022 *)
  • PARI
    row(n) = Vecrev(prod(j=1, n, (1+j)*x - j)); \\ Michel Marcus, Feb 24 2022
  • Sage
    def A142070(n,k): return (-1)^(n-k)*sum(binomial(j+n-k, n-k)*stirling_number1(n+1, k-j+1) for j in (0..k))
    flatten([[A142070(n, k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 24 2022
    

Formula

T(n, k) = [x^k]( Product_{j=1..n} ((1+j)*x - j) ).
Sum_{k=0..n} T(n, k) = 1.
From G. C. Greubel, Feb 24 2022: (Start)
T(n, k) = (-1)^(n-k) * Sum_{j=0..n} (-1)^j*binomial(j,n-k)*Stirling1(n+1, n-j+1).
T(n, k) = Sum_{j=0..k} (-1)^j*binomial(j+n-k,n-k)*Stirling1(n+1, k-j+1).
T(n, 0) = (-1)^n * n!.
T(n, n) = (n+1)!. (End)
Showing 1-2 of 2 results.