A103933 Denominators of first difference of squares of harmonic numbers A001008/A002805.

1, 4, 9, 48, 150, 90, 490, 2240, 11340, 2520, 152460, 83160, 2342340, 2522520, 540540, 11531520, 104144040, 110270160, 737176440, 775975200, 162954792, 56904848, 1368302936, 2141691552, 111546435000, 116008292400, 1084231348200

Offset: 1

Author

Wolfdieter Lang, Mar 24 2005

Keywords

• nonn
• easy
• frac

Comments

The corresponding numerators are given in A103932. For the rationals see the link there.

Programs

Mathematica

Denominator[Differences[HarmonicNumber[Range[0,30]]^2]] (* Harvey P. Dale, Sep 09 2012 *)

Formula

a(n)=numerator(r(n)), with the rationals r(n)=H(n)^2-H(n-1)^2 where H(n)= A001008(n)/A002805(n), n>=1, H(0):=0.

Extensions

Offset corrected by Mohammed Yaseen, Aug 09 2023