A135120 Numbers such that the digital sum base 2 and the digital sum base 3 and the digital sum base 10 all are equal.

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

Author

Hieronymus Fischer, Dec 24 2007

Keywords

• nonn
• base

Examples

			a(2)=21, since ds_2(21)=ds_3(21)=ds_10(21)=3.
		

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1100

Crossrefs

Cf. A000040, A007953, A054899, A131451, A133620, A133900, A134599, A135110.

Programs

Mathematica

Select[Range[5000], Total[IntegerDigits[#, 2]] == Total[IntegerDigits[#, 3]] ==  Total[IntegerDigits[#, 10]] &] (* G. C. Greubel, Sep 26 2016 *)

PARI

is(n)=my(t=sumdigits(n)); t==hammingweight(n) && t==sumdigits(n,3) \\ Charles R Greathouse IV, Sep 26 2016