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A073780
Number of 1's in base 3 representation of n-th prime.
3
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
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
Sequence in context: A336467 A331112 A029382 * A124389 A366789 A027023
KEYWORD
base,easy,nonn
AUTHOR
Zak Seidov Aug 11 2002
STATUS
approved