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A073781 Number of 2's in base-3 representation of n-th prime. 2
1, 0, 1, 1, 1, 0, 2, 1, 2, 1, 0, 0, 1, 1, 2, 3, 2, 2, 1, 3, 2, 3, 1, 2, 1, 2, 1, 3, 0, 1, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 3, 2, 2, 1, 3, 1, 2, 3, 3, 2, 4, 4, 4, 2, 1, 2, 3, 0, 1, 1, 0, 2, 1, 2, 2, 3, 1, 0, 2, 2, 1, 2, 1, 1, 1, 2, 2, 2, 3, 1, 2, 2, 4, 1, 2, 2, 3, 3 (list; graph; refs; listen; history; internal format)
OFFSET

1,7

EXAMPLE

a(7)=2 as 7th prime 17 is 122 in base-3 representation

MAPLE

a2[n_] := Length[Cases[IntegerDigits[Prime[n], 3], 2]]

CROSSREFS

Cf. A073779, A073780.

Sequence in context: A121310 A024356 A143947 * A048622 A105661 A082451

Adjacent sequences:  A073778 A073779 A073780 * A073782 A073783 A073784

KEYWORD

base,easy,nonn

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com) Aug 11 2002

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Last modified February 17 02:48 EST 2012. Contains 205978 sequences.