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 A033108 Number of 7's when k is written in base b for all b and k satisfying 2<=b<=n+1, 1<=k<=n. 10
 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, 15, 17, 18, 20, 21, 24, 25, 27, 29, 31, 32, 35, 36, 39, 41, 43, 44, 48, 49, 51, 53, 57, 58, 61, 62, 65, 68, 70, 71, 76, 78, 82, 85, 89, 91, 96, 99, 105, 108, 111, 113, 120 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,15 LINKS MATHEMATICA f[n_] := Count[ Flatten@ Table[ IntegerDigits[k, b], {k, n}, {b, 2, n + 1}], 7] - (n - 7); f[1] = f[2] = f[3] = f[4] = f[5] = f[6] = 0; Array[f, 67] (* Robert G. Wilson v, Nov 14 2012 *) CROSSREFS Cf. A033094, A033096, A033098, A033100, A033102, A033104, A033106, A033107, A033110, A033112. Sequence in context: A129946 A099649 A330982 * A049811 A124097 A180478 Adjacent sequences:  A033105 A033106 A033107 * A033109 A033110 A033111 KEYWORD nonn,base AUTHOR STATUS approved

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Last modified February 16 16:00 EST 2020. Contains 331961 sequences. (Running on oeis4.)