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