A027706 n-th prime has odd number of 1's in binary expansion and (n+1)st prime has even number of 1's.

1, 6, 8, 13, 15, 19, 22, 25, 29, 33, 37, 44, 54, 58, 61, 63, 65, 67, 73, 75, 78, 86, 88, 90, 95, 98, 100, 104, 107, 113, 116, 121, 123, 130, 132, 136, 138, 140, 145, 149, 151, 153, 158, 164, 169, 172, 175, 177, 181, 186, 189, 193, 198, 202, 205, 207, 210, 212, 220

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..2600

Mathematica

c[ n_ ] := OddQ[ Count[ IntegerDigits[ n, 2 ], 1 ] ]; Select[ Range[ 500 ], c[ Prime[ # ] ]&&Not[ c[ Prime[ #+1 ] ] ]& ]
SequencePosition[Table[If[OddQ[DigitCount[n, 2, 1]], 1, 0], {n, Prime[Range[ 300]]}], {1, 0}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 01 2019 *)

Crossrefs

Cf. A027705 (corresponding primes).

Cf. A027702, A027704, A027708.

Sequence in context: A160133 A057710 A285678 * A047336 A181449 A315874

Adjacent sequences: A027703 A027704 A027705 * A027707 A027708 A027709

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Erich Friedman

Offset changed by Michel Marcus, Mar 29 2018

Status

approved