

A227092


Numbers whose base7 sum of digits is 7.


9



13, 19, 25, 31, 37, 43, 55, 61, 67, 73, 79, 85, 91, 103, 109, 115, 121, 127, 133, 151, 157, 163, 169, 175, 199, 205, 211, 217, 247, 253, 259, 295, 301, 349, 355, 361, 367, 373, 379, 385, 397, 403, 409, 415, 421, 427, 445, 451, 457, 463, 469, 493, 499, 505
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OFFSET

1,1


COMMENTS

All of the entries are odd.
Subsequence of A016921.  Michel Marcus, Sep 03 2013
In general, the set of numbers with sum of baseb digits equal to b is a subset of { (b1)*k + 1; k = 2, 3, 4, ... }.  M. F. Hasler, Dec 23 2016


LINKS

Table of n, a(n) for n=1..54.


EXAMPLE

The 7ary expansion of 13 is (1,6), which has sum of digits 7.
The 7ary expansion of 103 is (2,0,5), which has sum of digits 7.
10 is not on the list since the 7ary expansion of 10 is (1,3), which has sum of digits 4 not 7.


MATHEMATICA

Select[Range[600], Total[IntegerDigits[#, 7]]==7&] (* Harvey P. Dale, Aug 18 2014 *)


PROG

(Sage) [i for i in [0..1000] if sum(Integer(i).digits(base=7))==7]
(PARI) select( is(n)=sumdigits(n, 7)==7, [1..999]) \\ M. F. Hasler, Dec 23 2016


CROSSREFS

Cf. A018900, A187813.
Cf. A226636 (b = 3), A226969 (b = 4), A227062 (b = 5), A227080 (b = 6), A227092 (b = 7), A227095 (b = 8), A227238 (b = 9), A052224 (b = 10).
Sequence in context: A214031 A250293 A058898 * A123840 A258589 A329930
Adjacent sequences: A227089 A227090 A227091 * A227093 A227094 A227095


KEYWORD

nonn,base


AUTHOR

Tom Edgar, Sep 01 2013


STATUS

approved



