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A227238
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Numbers whose base-9 sum of digits is 9.
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9
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17, 25, 33, 41, 49, 57, 65, 73, 89, 97, 105, 113, 121, 129, 137, 145, 153, 169, 177, 185, 193, 201, 209, 217, 225, 249, 257, 265, 273, 281, 289, 297, 329, 337, 345, 353, 361, 369, 409, 417, 425, 433, 441, 489, 497, 505, 513, 569, 577, 585, 649, 657, 737, 745
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OFFSET
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1,1
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COMMENTS
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All of the entries are odd.
In general, the set of numbers with sum of base-b digits equal to b is a subset of { (b-1)*k + 1; k = 2, 3, 4, ... }. - M. F. Hasler, Dec 23 2016
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LINKS
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EXAMPLE
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The 9-ary expansion of 17 is (1,8), which has sum of digits 9.
The 9-ary expansion of 169 is (2,0,7), which has sum of digits 9.
10 is not on the list since the 9-ary expansion of 10 is (1,1), which has sum of digits 2 not 9.
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MATHEMATICA
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Select[Range@ 750, Total@ IntegerDigits[#, 9] == 9 &] (* Michael De Vlieger, Dec 23 2016 *)
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PROG
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(Sage) [i for i in [0..1000] if sum(Integer(i).digits(base=9))==9]
(PARI) select( is(n)=sumdigits(n, 9)==9, [1..999]) \\ M. F. Hasler, Dec 23 2016
(Python)
agen = A226636gen(sod=9, base=9) # generator of terms using code in A226636
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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