A027698 - OEIS

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A027698

Numbers k such that the k-th prime has an odd number of 1's in its binary expansion.

1, 4, 5, 6, 8, 11, 12, 13, 15, 17, 18, 19, 21, 22, 25, 27, 28, 29, 31, 32, 33, 36, 37, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 54, 58, 61, 63, 65, 67, 73, 75, 78, 80, 81, 82, 83, 84, 85, 86, 88, 90, 93, 94, 95, 98, 100, 102, 103, 104, 106, 107, 110, 111, 112

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[ Range[ 150 ], OddQ[ Length[ Cases[ IntegerDigits[ Prime[ # ], 2 ], 1 ] ] ]& ]

Select[Range[200], OddQ[DigitCount[Prime[#], 2, 1]]&] (* Harvey P. Dale, Sep 19 2021 *)

CROSSREFS

Cf. A027697, A027699, A027700.

Sequence in context: A035065 A209722 A035067 * A047313 A030343 A030590

Adjacent sequences: A027695 A027696 A027697 * A027699 A027700 A027701