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.

A341725 Triangle read by rows: coefficients in expansion of Asveld's polynomials p_j(x).

Original entry on oeis.org

1, 3, 1, 13, 6, 1, 81, 39, 9, 1, 673, 324, 78, 12, 1, 6993, 3365, 810, 130, 15, 1, 87193, 41958, 10095, 1620, 195, 18, 1, 1268361, 610351, 146853, 23555, 2835, 273, 21, 1, 21086113, 10146888, 2441404, 391608, 47110, 4536, 364, 24, 1
Offset: 0

Views

Author

N. J. A. Sloane, Mar 04 2021

Keywords

Examples

			Triangle begins:
      1,
      3,     1,
     13,     6,     1,
     81,    39,     9,    1,
    673,   324,    78,   12,   1,
   6993,  3365,   810,  130,  15,  1,
  87193, 41958, 10095, 1620, 195, 18, 1,
  ...
		

References

  • Anthony G. Shannon and Richard L. Ollerton. "A note on Ledin’s summation problem." The Fibonacci Quarterly 59:1 (2021), 47-56. See Table 5.

Crossrefs

Column 0 is A005923, column 1 is A341728.

Programs

  • Maple
    egf:= k-> exp(x)*x^k / ((1-2*sinh(x))*k!):
    A341725:= (n, k)-> n! * coeff(series(egf(k), x, n+1), x, n):
    seq(print(seq(A341725(n, k), k=0..n)), n=0..8); # Mélika Tebni, Sep 04 2023

Formula

From Mélika Tebni, Sep 04 2023: (Start)
T(n,k) = binomial(n,k)*A005923(n-k).
E.g.f. of column k: exp(x)*x^k / ((1-2*sinh(x))*k!).
T(n,k) = Sum_{j=k..n} binomial(n,j)*A000557(n-j)*binomial(j,k).
Recurrence: T(n,0) = A005923(n) and T(n,k) = n*T(n-1,k-1) / k, n >= k >= 1. (End)
Sum_{k=0..n} (-1)^k * T(n,k) = A000557(n). - Alois P. Heinz, Sep 04 2023

Extensions

More terms from Mélika Tebni, Sep 04 2023