A076175 Denominator of Sum_{i+j+k=n, i,j,k>=1} (i*j)/k.

1, 1, 1, 2, 3, 12, 15, 30, 21, 168, 126, 1260, 990, 792, 1287, 18018, 5005, 80080, 68068, 58344, 50388, 201552, 176358, 3879876, 3432198, 27457584, 24515700, 637408200, 573667380, 16062686640, 29113619535, 26466926850, 24131609775

Offset: 1

Author

Benoit Cloitre, Nov 01 2002

Keywords

• frac
• nonn

Crossrefs

Cf. A076174.

Programs

PARI

a(n)=denominator(sum(i=1,n,sum(j=1,n,sum(k=1,n,if(n-i-j-k,0,1)*i*j/k))))