A245417 Number of nonnegative integers with property that their base 7/3 expansion (see A024640) has n digits.

7, 14, 28, 70, 161, 378, 882, 2058, 4802, 11200, 26138, 60984, 142296, 332024, 774725, 1807694, 4217948, 9841881, 22964389, 53583572, 125028337, 291732784, 680709834, 1588322946, 3706086874, 8647536037, 20177584084, 47081029534, 109855735577, 256330049682

Offset

1,1

Links

Table of n, a(n) for n=1..30.

Example

The only integers requiring two digits in base 7/3 are 30, 31, 32, 33, 34, 35, 36, 60, 61, 62, 63, 64, 65, 66, representing 7-20 respectively; thus, a(2) = 14.

Prog

(Sage)
A=[1]
for i in [1..100]:
    A.append(ceil(((7-3)/3)*sum(A)))
[7*x for x in A]

Crossrefs

Cf. A245356, A081848, A024640.

Sequence in context: A115876 A005009 A135092 * A348111 A332371 A058530

Adjacent sequences: A245414 A245415 A245416 * A245418 A245419 A245420

Keyword

nonn,base

Author

Tom Edgar, Jul 21 2014

Status

approved