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A245342 Sum of digits of n written in fractional base 7/2. 0
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, 3, 4, 5, 6, 7, 8, 9, 5, 6, 7, 8, 9, 10, 11, 7, 8, 9, 10, 11, 12, 13, 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, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

The base 7/2 expansion is unique and thus the sum of digits function is well-defined.

LINKS

Table of n, a(n) for n=0..77.

FORMULA

a(n) = A007953(A024639(n)).

EXAMPLE

In base 7/2 the number 14 is represented by 40 and so a(14) = 4 + 0 = 4.

PROG

(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]]

CROSSREFS

A007953, A000120, A024639, A053828, A244040

Sequence in context: A105257 A125937 A173526 * A203580 A043266 A082120

Adjacent sequences:  A245339 A245340 A245341 * A245343 A245344 A245345

KEYWORD

nonn,base

AUTHOR

Hailey R. Olafson, Jul 18 2014

STATUS

approved

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Last modified October 14 14:06 EDT 2019. Contains 328017 sequences. (Running on oeis4.)