A229284 Number of ascending runs in {1,...,10}^n.

0, 10, 155, 2100, 26500, 320000, 3750000, 43000000, 485000000, 5400000000, 59500000000, 650000000000, 7050000000000, 76000000000000, 815000000000000, 8700000000000000, 92500000000000000, 980000000000000000, 10350000000000000000, 109000000000000000000

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..990

Index entries for linear recurrences with constant coefficients, signature (20,-100).

Formula

G.f.: -5*(9*x-2)*x/(10*x-1)^2.

a(n) = 10^(n-1)*(11*n+9)/2 for n>0, a(0) = 0.

Maple

a:= n-> `if`(n=0, 0, 10^(n-1)*(11*n+9)/2):
seq(a(n), n=0..30);

Crossrefs

Column k=10 of A229079.

Sequence in context: A298081 A240374 A261744 * A087603 A292837 A261802

Adjacent sequences: A229281 A229282 A229283 * A229285 A229286 A229287

Keyword

nonn,easy

Author

Alois P. Heinz, Sep 18 2013

Status

approved