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A245423
Number of nonnegative integers with property that their base 7/5 expansion (see A024642) has n digits.
0
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
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
Sequence in context: A246506 A001733 A266952 * A242889 A092076 A117981
KEYWORD
nonn,base
AUTHOR
James Van Alstine, Jul 21 2014
STATUS
approved