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.

A341102 T(n, k) = [n, k] - {n, k}, where [n, k] are the (unsigned) Stirling cycle numbers and {n, k} the Stirling set numbers. Table T(n, k) read by rows, for n >= 3 and 1 <= k <= n-2.

Original entry on oeis.org

1, 5, 4, 23, 35, 10, 119, 243, 135, 20, 719, 1701, 1323, 385, 35, 5039, 12941, 12166, 5068, 910, 56, 40319, 109329, 115099, 59514, 15498, 1890, 84, 362879, 1026065, 1163370, 689575, 226800, 40446, 3570, 120, 3628799, 10627617, 12725075, 8263750, 3170200, 722568, 93786, 6270, 165
Offset: 3

Views

Author

Peter Luschny, Feb 24 2021

Keywords

Examples

			Triangle starts:
[ 3] [1]
[ 4] [5,      4]
[ 5] [23,     35,      10]
[ 6] [119,    243,     135,     20]
[ 7] [719,    1701,    1323,    385,    35]
[ 8] [5039,   12941,   12166,   5068,   910,    56]
[ 9] [40319,  109329,  115099,  59514,  15498,  1890,  84]
[10] [362879, 1026065, 1163370, 689575, 226800, 40446, 3570, 120]
		

Crossrefs

Programs

  • Maple
    # Giving full rows for n >= 0:
    gf := (1 - z)^(-x) - exp(x*(exp(z) - 1));
    ser := series(gf, z, 20): coeffz := n -> coeff(ser,z,n):
    A341102row := n -> seq(n!*coeff(coeffz(n), x, k), k=0..n):
    for n from 0 to 9 do A341102row(n) od;
  • PARI
    T(n,k) = abs(stirling(n,k,1)) - stirling(n,k,2); \\ Michel Marcus, Feb 24 2021
  • SageMath
    for n in (3..11):
        print([stirling_number1(n, k) - stirling_number2(n, k) for k in (1..n-2)])
    

Formula

T(n, k) = Sum_{j=0..k} (binomial(n+j-1, 2*k) - binomial(n+k-j, 2*k))*A340556(k, j).
E.g.f.: (1 - z)^(-x) - exp(x*(exp(z) - 1)) (unrestricted rows and n >= 0).