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

0,2

Links

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

Mathematica

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

Crossrefs

Cf. A003592.

Sequence in context: A295979 A338488 A365418 * A200184 A005286 A298877

Adjacent sequences: A180950 A180951 A180952 * A180954 A180955 A180956

Keyword

base,nonn

Author

Robert G. Wilson v, Sep 27 2010

Status

approved