A245423 Number of nonnegative integers with property that their base 7/5 expansion (see A024642) has n digits.

7, 7, 7, 14, 14, 21, 28, 42, 56, 84, 112, 161, 224, 315, 441, 616, 861, 1204, 1687, 2366, 3311, 4634, 6489, 9086, 12719, 17808, 24927, 34902, 48860, 68404, 95767, 134071, 187698, 262780, 367892, 515046, 721070, 1009498, 1413293, 1978613, 2770054, 3878077

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Example

The numbers 7-13 are represented by 50, 51, 52, 53, 54, 55, 56 respectively in base 7/5. These are the only integers with two digits, and so a(2)=7.

Prog

(Sage)
A=[1]
for i in [1..60]:
    A.append(ceil((7-5)/5*sum(A)))
[7*x for x in A]

Crossrefs

Cf. A024642, A081848.

Sequence in context: A246506 A001733 A266952 * A242889 A092076 A117981

Adjacent sequences: A245420 A245421 A245422 * A245424 A245425 A245426

Keyword

nonn,base

Author

James Van Alstine, Jul 21 2014

Status

approved