A245431 Number of nonnegative integers with property that their base 10/7 expansion has n digits.

10, 10, 10, 20, 30, 40, 60, 80, 120, 170, 240, 340, 490, 700, 1000, 1430, 2040, 2910, 4160, 5940, 8490, 12130, 17330, 24750, 35360, 50520, 72170, 103100, 147280, 210400, 300570, 429390, 613410, 876300, 1251860, 1788370, 2554820, 3649740, 5213910, 7448450

Offset: 1

Author

Hailey R. Olafson, Jul 21 2014

Keywords

• nonn
• base

Comments

See A024662 for an explanation of base 10/7.

Examples

			a(2) = 10 because 70, 71, 72, 73, 74, 75, 76, 77, 78 and 79 are the base 10/7 expansions for the integers 10, 11, 12, 13, 14, 15, 16, 17, 18 and 19 respectively and these are the only integers with 2 digits.
		

Crossrefs

Cf. A024662, A081848, A245356.

Programs

Sage

A=[1]
for i in [1..60]:
    A.append(ceil(((10-7)/7)*sum(A)))
[10*x for x in A]