A203580 a(n) = Sum{d(i)*2^i: i=0,1,...,m}, where Sum{d(i)*7^i: i=0,1,...,m}=n, d(i)∈{0,1,...,6}.
0, 1, 2, 3, 4, 5, 6, 2, 3, 4, 5, 6, 7, 8, 4, 5, 6, 7, 8, 9, 10, 6, 7, 8, 9, 10, 11, 12, 8, 9, 10, 11, 12, 13, 14, 10, 11, 12, 13, 14, 15, 16, 12, 13, 14, 15, 16, 17, 18, 4, 5, 6, 7, 8, 9, 10, 6, 7, 8, 9, 10, 11, 12, 8, 9, 10, 11, 12, 13, 14, 10, 11, 12, 13, 14
Offset: 0
Links
- Clark Kimberling, Table of n, a(n) for n = 0..1000
Crossrefs
Cf. A033044.
Programs
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Mathematica
t = Table[FromDigits[RealDigits[n, 7], 2], {n, 0, 100}] (* Clark Kimberling, Aug 03 2012 *)
Formula
a(0)=0, a(n)=2*a(n/7) if n==0 (mod 7), a(n)=a(n-1)+1 otherwise.
Comments