A113978 a(n)=Sum(d|n)(10^(n-d)).

1, 11, 101, 1101, 10001, 111001, 1000001, 11010001, 101000001, 1100100001, 10000000001, 111101000001, 1000000000001, 11000010000001, 101010000000001, 1101000100000001, 10000000000000001, 111001001000000001

Offset

0,2

Comments

A074854 in base 2. Stacking the elements gives the triangle A051731.

Links

Table of n, a(n) for n=0..17.

Formula

G.f.: Sum_{k>0} 10^(k-1)*x^k/(1-10^(k-1)*x^k).

Prog

(PARI) a(n)=if(n<1, 0, 10^n*polcoeff(sum(k=1, n, 10/(10-x^k), x*O(x^n)), n))

Crossrefs

Sequence in context: A199306 A282958 A283061 * A284141 A283910 A273912

Adjacent sequences: A113975 A113976 A113977 * A113979 A113980 A113981

Keyword

easy,nonn

Author

Paul Barry, Nov 11 2005

Status

approved