A073780 Number of 1's in base 3 representation of n-th prime.

0, 1, 1, 1, 1, 3, 1, 1, 1, 1, 3, 3, 3, 3, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 3, 3, 3, 3, 1, 3, 3, 3, 3, 1, 1, 1, 1, 1, 1, 3, 1, 3, 3, 1, 1, 3, 1, 1, 1, 1, 3, 1, 1, 3, 3, 3, 5, 3, 3, 3, 3, 1, 3, 5, 3, 3, 3, 3, 5, 5, 3, 3, 3, 3, 3, 3, 3, 3, 1, 3, 3, 3, 3, 3

Offset

1,6

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

a(n) = A062756(A000040(n)). - Michel Marcus, Oct 02 2013

Example

a1(11)=3 as 11th prime, 31, is 1011 in base 3 representation.

Mathematica

a1[n_] := Length[Cases[IntegerDigits[Prime[n], 3], 1]]
Table[DigitCount[n, 3, 1], {n, Prime[Range[100]]}] (* Harvey P. Dale, Feb 23 2015 *)

Crossrefs

Cf. A073779, A073781.

Sequence in context: A336467 A331112 A029382 * A124389 A366789 A027023

Adjacent sequences: A073777 A073778 A073779 * A073781 A073782 A073783

Keyword

base,easy,nonn

Author

Zak Seidov Aug 11 2002

Status

approved