[go: up one dir, main page]

login
A135120
Numbers such that the digital sum base 2 and the digital sum base 3 and the digital sum base 10 all are equal.
10
1, 21, 222, 223, 1230, 1231, 1502, 2200, 2201, 3012, 3013, 10431, 12214, 12215, 12250, 12251, 14102, 15003, 15021, 16011, 20040, 20041, 22130, 23211, 23230, 23231, 24003, 30070, 30071, 30105, 30231, 30321, 31005, 31150, 31151, 31420
OFFSET
1,2
LINKS
EXAMPLE
a(2)=21, since ds_2(21)=ds_3(21)=ds_10(21)=3.
MATHEMATICA
Select[Range[5000], Total[IntegerDigits[#, 2]] == Total[IntegerDigits[#, 3]] == Total[IntegerDigits[#, 10]] &] (* G. C. Greubel, Sep 26 2016 *)
PROG
(PARI) is(n)=my(t=sumdigits(n)); t==hammingweight(n) && t==sumdigits(n, 3) \\ Charles R Greathouse IV, Sep 26 2016
KEYWORD
nonn,base
AUTHOR
Hieronymus Fischer, Dec 24 2007
STATUS
approved