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.

A103994 A129360 * A115361.

Original entry on oeis.org

1, 1, 1, -1, 0, 1, 1, 1, 0, 1, -1, 0, 0, 0, 1, -1, -1, 1, 0, 0, 1, -1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, -1, 0, 0, 0, 0, 0, 1, -1, -1, 0, 0, 1, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, -1, 1, -1, 0, 1, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
Offset: 1

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Author

Gary W. Adamson, Apr 15 2007

Keywords

Comments

Row sums = A104117: (1, 2, 0, 3, 0, 0, 0, 4, 0, 0, ...).

Examples

			First few rows of the triangle are:
   1;
   1,  1;
  -1,  0,  1;
   1,  1,  0,  1;
  -1,  0,  0,  0,  1;
  -1, -1,  1,  0,  0,  1;
  -1,  0,  0,  0,  0,  0,  1;
   1,  1,  0,  1,  0,  0,  0,  1;
   ...
		

Crossrefs

Column 1 is A209635 (Moebius transform of A104117).
Row sums are A104117.

Programs

  • Mathematica
    T[n_, k_] := If[Divisible[n, k], MoebiusMu[(n/k)/2^IntegerExponent[n/k, 2]], 0];
    Table[T[n, k], {n, 1, 13}, {k, 1, n}] // Flatten (* Jean-François Alcover, Sep 14 2019 *)
  • PARI
    tabl(nn) = {Tm = matrix(nn, nn, n, k, if (! (n % k), moebius(n/k), 0)); Tr = matrix(nn, nn, n, k, n--; k--; if ((n==k), 1, if (n==2*k+1, -1, 0))); Ti = Tr^(-1); Tp = Tm*Ti*Ti; for (n=1, nn, for (k=1, n, print1(Tp[n, k], ", ");); print(););}
    
  • PARI
    T(n, k)={ if(n%k, 0, sumdiv(n/k, d, my(e=valuation(d, 2)); if(d==1<Andrew Howroyd, Aug 03 2018

Formula

A129360 * A115361 as infinite lower triangular matrices.
T(n,k) = A209635(n/k) for k | n, T(n,k) = 0 otherwise. - Andrew Howroyd, Aug 03 2018

Extensions

More terms from Michel Marcus, Mar 28 2015