A164945 Decimal value of the concatenation of first n multiples of 3 in binary.

3, 30, 489, 7836, 125391, 4012530, 128400981, 4108831416, 131482605339, 4207443370878, 269276375736225, 17233688047118436, 1102956035015579943, 70589186240997116394, 4517707919423815449261, 289133306843124188752752

Offset

1,1

Links

Table of n, a(n) for n=1..16.

Example

a(3)=489 because the first 3 multiples of 3 in binary are 11 110 1001, and the concatenation 111101001 in base 10 = 489. a(4)=7836 because the first 4 3 multiples of 3 in binary are 11 110 1001 1100, and the concatenation 1111010011100 in base 10 = 7836.

Mathematica

Module[{nn=20, tb}, tb=IntegerDigits[3*Range[nn], 2]; Table[FromDigits[ Flatten[ Take[tb, n]], 2], {n, nn}]] (* Harvey P. Dale, Oct 11 2017 *)

Crossrefs

Sequence in context: A242005 A276356 A012003 * A354252 A354261 A201466

Adjacent sequences: A164942 A164943 A164944 * A164946 A164947 A164948

Keyword

base,easy,nonn

Author

Gil Broussard, Sep 01 2009

Status

approved