A106600 Number of positive integers <= 10^n that are divisible by no prime exceeding 7.

1, 10, 46, 141, 338, 694, 1273, 2155, 3427, 5194, 7575, 10688, 14672, 19674, 25861, 33406, 42487, 53302, 66061, 80988, 98311, 118271, 141124, 167139, 196597, 229785, 267007, 308575, 354820, 406074, 462692, 525030, 593467, 668384, 750177, 839260

Offset: 0

Author

Robert G. Wilson v, May 27 2005

Keywords

• nonn

Comments

Position of 10^n among the 7-smooth numbers (A002473). Note that all powers of 10 are in A002473. - Zak Seidov, Nov 18 2013

Examples

			A002473(a(2)) = A002473(46)=100.
		

Links

• Zak Seidov, Table of n, a(n) for n = 0..200

Crossrefs

Row 4 of A253635.

Cf. A002473, A011557.

Programs

Mathematica

n = 35; t = Select[ Flatten[ Table[ 7^d*Select[ Flatten[ Table[ 5^c*Select[ Flatten[ Table[2^a*3^b, {a, 0, n*Log[2, 10]}, {b, 0, n*Log[3, 10]}]], # <= 10^n &], {c, 0, n*Log[5, 10]}]], # <= 10^n &], {d, 0, n*Log[5, 10]}]], # <= 10^n &]; Table[ Length[ Select[t, # <= 10^n &]], {n, 0, 35}]