A245402 Number of nonnegative integers with property that their base 7/6 expansion (see A024643) has n digits.
7, 7, 7, 7, 7, 7, 7, 14, 14, 14, 21, 21, 28, 28, 35, 42, 49, 56, 63, 77, 91, 105, 119, 140, 161, 189, 224, 259, 301, 350, 413, 483, 560, 651, 763, 889, 1036, 1211, 1414, 1645, 1925, 2240, 2618, 3052, 3563, 4158, 4851, 5656, 6601, 7700, 8981, 10479, 12229, 14266
Offset: 1
Examples
a(3) = 7 because 650, 651, 652, 653, 654, 655 and 656 are the base 7/6 expansions for the integers 14, 15, 16, 17, 18, 19 and 20 respectively and these are the only integers with 3 digits.
Programs
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Sage
A=[1] for i in [1..60]: A.append(ceil(((7-6)/6)*sum(A))) [7*x for x in A]
Formula
a(n) = 7*A120178(n).