A143750 a(n)=10^C(n,2)*(1-10^n)/9.

0, -1, -110, -111000, -1111000000, -111110000000000, -111111000000000000000, -1111111000000000000000000000, -111111110000000000000000000000000000, -111111111000000000000000000000000000000000000

Offset

0,3

Comments

Hankel transform of A143749.

Links

Table of n, a(n) for n=0..9.

Formula

a(n)=-10^C(n,2)*A002275(n);

Crossrefs

Sequence in context: A329126 A329338 A203718 * A371032 A192844 A234512

Adjacent sequences: A143747 A143748 A143749 * A143751 A143752 A143753

Keyword

easy,sign

Author

Paul Barry, Aug 30 2008

Status

approved