A180953 The number of terms of the form 2^i*5^j (A003592) less than or equal to 10^n.

1, 6, 15, 29, 48, 72, 100, 134, 172, 214, 262, 314, 371, 433, 500, 571, 647, 728, 813, 904, 999, 1099, 1204, 1313, 1427, 1546, 1670, 1798, 1932, 2070, 2212, 2359, 2511, 2668, 2829, 2996, 3167, 3342, 3523, 3708, 3898, 4093, 4293, 4497, 4706, 4920, 5138

Offset: 0

Author

Robert G. Wilson v, Sep 27 2010

Keywords

• base
• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A003592.

Programs

Mathematica

f[n_] := Sum[1 + Floor@ Log[2, 10^n/5^k], {k, 0, Floor@ Log[5, 10^n]}]; Array[f, 47, 0]