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.

A156653 Triangle T(n,k) = ((-1)^(n+k)/(n+1))*Sum_{j=0..n} (-1)^j*j!*Stirling2(n, j)* binomial(n-j, k)*binomial(n+j, j), read by rows.

Original entry on oeis.org

1, 1, 3, 1, 16, 13, 1, 125, 171, 39, 1, 1296, 2551, 1091, 101, 1, 16807, 43653, 28838, 5498, 243, 1, 262144, 850809, 780585, 243790, 24270, 561, 1, 4782969, 18689527, 22278189, 10073955, 1733035, 98661, 1263, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 12 2009

Keywords

Comments

Row sums are A001761.

Examples

			Triangle begins as:
          1;
          1;
          3,         1;
         16,        13,         1;
        125,       171,        39,         1;
       1296,      2551,      1091,       101,         1;
      16807,     43653,     28838,      5498,       243,        1;
     262144,    850809,    780585,    243790,     24270,      561,      1;
    4782969,  18689527,  22278189,  10073955,   1733035,    98661,   1263,    1;
  100000000, 457947691, 677785807, 410994583, 106215619, 10996369, 379693, 2797, 1;
		

Crossrefs

Programs

  • Magma
    A156653:= func< n,k | ((-1)^(n+k)/(n+1))*(&+[ (-1)^j*Factorial(j)*StirlingSecond(n, j)*Binomial(n-j, k)*Binomial(n+j, j) : j in [0..n]]) >;
    [1] cat [A156653(n,k): k in [0..n-1], n in [1..12]]; // G. C. Greubel, Mar 01 2021
    
  • Mathematica
    T[n_, m_]:= Sum[(-1)^(n+m+k) k! StirlingS2[n, k] Binomial[n-k, m] Binomial[n+k, k], {k, 0, n}]/(n+1);
    Prepend[Table[T[n, m], {n,10}, {m, 0, n-1}]//Flatten, 1] (* Peter Luschny, May 11 2020 *)
  • Maxima
    T(n,m):=sum(k!*stirling2(n,k)*(-1)^(n+m+k)*binomial(n-k,m)*binomial(n+k,k),k,0,n) /(n+1); /* Vladimir Kruchinin, May 11 2020 */
    
  • Sage
    def A156653(n,k): return ((-1)^(n+k)/(n+1))*sum( (-1)^j*factorial(j)* stirling_number2(n, j)*binomial(n-j, k)*binomial(n+j, j) for j in (0..n))
    [1]+flatten([[A156653(n,k) for k in (0..n-1)] for n in (1..12)]) # G. C. Greubel, Mar 01 2021

Formula

T(n, m) = [x^m] p(x,n) where p(x,n) = (1-x)^(2*n+1)/((n+1)*x^n)*Sum_{k>=0} (k+1)^n* binomial(k, n)*x^k.
T(n, m) = 1/(n+1)*Sum_{k=0..n} (-1)^(n+m+k)*k!*Stirling2(n,k)*C(n-k,m)*C(n+k,k). - Vladimir Kruchinin, May 05 2020
E.g.f. satisfies: A(x,y) = x*E(A(x,y),y), where E(x,y) is e.g.f. of Euler numbers of first kind A008292. - Vladimir Kruchinin, May 05 2020

Extensions

New name by Vladimir Kruchinin, May 11 2020