OFFSET
0,3
REFERENCES
A. Cobham, Uniform Tag Sequences, Mathematical Systems Theory, 6 (1972), 164-192.
FORMULA
n (base 6) = A007092(n) A007092(0)=0, A007092(n)=10* A007092(n/6) if n==0 (mod 6), A007092(n)= A007092(n-1)+1 otherwise. - Benoit Cloitre, Dec 22 2002
a(n) below is Sum_{i=0..n} first-digit{(i base 6)}.
a(n) = Sum_{i=1..n} floor(n / 6^floor(log_6(n))) where log_6(n) is the logarithm to base 6.
a(n+1) = a(n) + first-digit-of((n+1) (base 6)).
EXAMPLE
n Base 6 Initial Cumulative Sum
0 0 0 0
1 1 1 1
2 2 2 3
3 3 3 6
4 4 4 10
5 5 5 15
MATHEMATICA
Accumulate[Table[First[IntegerDigits[n, 6]], {n, 0, 70}]] (* Harvey P. Dale, Oct 07 2012 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Jonathan Vos Post, Aug 30 2005
STATUS
approved