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.

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

Links

Table of n, a(n) for n=1..56.

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 *)

Crossrefs

Cf. A033094, A033096, A033098, A033099, A033102, A033104, A033106, A033108, A033110, A033112.

Sequence in context: A238486 A238482 A368483 * A030741 A190269 A304632

Adjacent sequences: A033097 A033098 A033099 * A033101 A033102 A033103

Keyword

nonn,base

Author

Clark Kimberling

Status

approved