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A033100
Number of 3's when k is written in base b for all b and k satisfying 2<=b<=n+1, 1<=k<=n.
10
0, 0, 1, 1, 1, 1, 2, 3, 4, 5, 7, 9, 12, 14, 19, 21, 24, 28, 33, 35, 40, 43, 49, 53, 57, 60, 68, 73, 78, 84, 92, 95, 103, 107, 114, 119, 124, 130, 140, 145, 151, 158, 169, 175, 185, 191, 200, 209, 216, 222, 235, 242, 251, 260, 271, 278
OFFSET
1,7
MATHEMATICA
f[n_] := Count[ Flatten@ Table[ IntegerDigits[k, b], {k, n}, {b, 2, n + 1}], 3] - (n - 3); f[1] = f[2] = 0; Array[f, 56] (* Robert G. Wilson v, Nov 14 2012 *)
KEYWORD
nonn,base
STATUS
approved