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A113978
a(n)=Sum(d|n)(10^(n-d)).
0
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.
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
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Nov 11 2005
STATUS
approved