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0,3
The base 7/2 expansion is unique and thus the sum of digits function is well-defined.
Table of n, a(n) for n=0..77.
a(n) = A007953(A024639(n)).
In base 7/2 the number 14 is represented by 40 and so a(14) = 4 + 0 = 4.
(Sage)
def base72sum(n):
....L=[n]
....i=1
....while L[i-1]>=7:
........x=L[i-1]
........L[i-1]=x.mod(7)
........L.append(2*floor(x/7))
........i+=1
....return sum(L)
[base72sum(w) for w in [0..200]]
A007953, A000120, A024639, A053828, A244040
Sequence in context: A105257 A125937 A173526 * A203580 A043266 A082120
Adjacent sequences: A245339 A245340 A245341 * A245343 A245344 A245345
nonn,base
Hailey R. Olafson, Jul 18 2014
approved