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.

A346148 Square array read by descending antidiagonals: T(n, k) = mu^n(k) where mu^1(k) = mu(k) = A008683(k) and for each n >= 1, mu^(n+1)(k) is the Dirichlet convolution of mu(k) and mu^n(k).

Original entry on oeis.org

1, -1, 1, -1, -2, 1, 0, -2, -3, 1, -1, 1, -3, -4, 1, 1, -2, 3, -4, -5, 1, -1, 4, -3, 6, -5, -6, 1, 0, -2, 9, -4, 10, -6, -7, 1, 0, 0, -3, 16, -5, 15, -7, -8, 1, 1, 1, -1, -4, 25, -6, 21, -8, -9, 1, -1, 4, 3, -4, -5, 36, -7, 28, -9, -10, 1, 0, -2, 9, 6, -10, -6
Offset: 1

Views

Author

Sebastian Karlsson, Aug 20 2021

Keywords

Examples

			  n\k| 1    2    3    4    5    6    7    8    9   10   11    12 ...
  ---+--------------------------------------------------------------
   1 | 1   -1   -1    0   -1    1   -1    0    0    1   -1     0 ...
   2 | 1   -2   -2    1   -2    4   -2    0    1    4   -2    -2 ...
   3 | 1   -3   -3    3   -3    9   -3   -1    3    9   -3    -9 ...
   4 | 1   -4   -4    6   -4   16   -4   -4    6   16   -4   -24 ...
   5 | 1   -5   -5   10   -5   25   -5  -10   10   25   -5   -50 ...
   6 | 1   -6   -6   15   -6   36   -6  -20   15   36   -6   -90 ...
   7 | 1   -7   -7   21   -7   49   -7  -35   21   49   -7  -147 ...
   8 | 1   -8   -8   28   -8   64   -8  -56   28   64   -8  -224 ...
   9 | 1   -9   -9   36   -9   81   -9  -84   36   81   -9  -324 ...
  10 | 1  -10  -10   45  -10  100  -10 -120   45  100  -10  -450 ...
  11 | 1  -11  -11   55  -11  121  -11 -165   55  121  -11  -605 ...
  12 | 1  -12  -12   66  -12  144  -12 -220   66  144  -12  -792 ...
  13 | 1  -13  -13   78  -13  169  -13 -286   78  169  -13 -1014 ...
  14 | 1  -14  -14   91  -14  196  -14 -364   91  196  -14 -1274 ...
  15 | 1  -15  -15  105  -15  225  -15 -455  105  225  -15 -1575 ...
  ...
		

Crossrefs

Main diagonal gives A341837.

Programs

  • Mathematica
    T[n_, k_] := If[k == 1, 1, Product[(-1)^e Binomial[n, e], {e, FactorInteger[k][[All, 2]]}]];
    Table[T[n-k+1, k], {n, 1, 12}, {k, n, 1, -1}] // Flatten (* Jean-François Alcover, Sep 13 2021 *)
  • PARI
    T(n, k) = my(f=factor(k)); for (k=1, #f~, f[k,1] = binomial(n, f[k,2])*(-1)^f[k,2]; f[k,2]=1); factorback(f); \\ Michel Marcus, Aug 21 2021
  • Python
    from sympy import binomial, primefactors as pf, multiplicity as mult
    from math import prod
    def T(n, k):
        return prod((-1)**mult(p, k)*binomial(n, mult(p, k)) for p in pf(k))
    

Formula

If k = Product (p_j^m_j) then T(n, k) = Product (binomial(n, m_j)*(-1)^m_j).
Dirichlet g.f. of the n-th row: 1/zeta^n(s).
T(n, p) = -n.
T(n, n) = A341837(n).