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A033107 Number of 7's when n is written in base b for 2<=b<=n+1. 10
0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 3, 2, 2, 1, 4, 1, 2, 2, 4, 1, 3, 1, 3, 3, 2, 1, 5, 2, 4, 3, 4, 2, 5, 3, 6, 3, 3, 2, 7, 2, 3, 5, 6, 3, 5, 2, 4, 3, 6, 3, 9, 2, 3, 4, 4, 4, 6, 3, 8, 4, 3, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,23

LINKS

Table of n, a(n) for n=1..90.

MATHEMATICA

f[n_] := Count[Flatten@ Table[ IntegerDigits[n, b], {b, 2, n + 1}], 7]; Array[f, 90] (* Robert G. Wilson v, Nov 14 2012 *)

CROSSREFS

Cf. A033093, A033095, A033097, A033099, A033101, A033103, A033105, A033108, A033109, A033111.

Sequence in context: A051881 A081757 A323880 * A239061 A309025 A247599

Adjacent sequences:  A033104 A033105 A033106 * A033108 A033109 A033110

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified January 27 12:01 EST 2020. Contains 331295 sequences. (Running on oeis4.)