A372539 Numbers k such that the number of ones minus the number of zeros in the binary expansion of the k-th prime number is -1.

7, 19, 21, 25, 56, 57, 59, 60, 62, 68, 71, 77, 79, 87, 175, 177, 179, 180, 186, 188, 189, 192, 193, 195, 196, 197, 204, 210, 212, 216, 218, 243, 244, 248, 254, 262, 263, 265, 279, 567, 572, 576, 577, 583, 592, 598, 599, 600, 602, 603, 605, 606, 610, 613, 616

Offset

1,1

Links

Table of n, a(n) for n=1..55.

Example

The binary expansion of 17 is (1,0,0,0,1) with ones minus zeros 2 - 3 = -1, and 17 is the 7th prime, 7 is in the sequence.
The primes A000040(a(n)) together with their binary expansions and binary indices begin:
    17:         10001 ~ {1,5}
    67:       1000011 ~ {1,2,7}
    73:       1001001 ~ {1,4,7}
    97:       1100001 ~ {1,6,7}
   263:     100000111 ~ {1,2,3,9}
   269:     100001101 ~ {1,3,4,9}
   277:     100010101 ~ {1,3,5,9}
   281:     100011001 ~ {1,4,5,9}
   293:     100100101 ~ {1,3,6,9}
   337:     101010001 ~ {1,5,7,9}
   353:     101100001 ~ {1,6,7,9}
   389:     110000101 ~ {1,3,8,9}
   401:     110010001 ~ {1,5,8,9}
   449:     111000001 ~ {1,7,8,9}
  1039:   10000001111 ~ {1,2,3,4,11}
  1051:   10000011011 ~ {1,2,4,5,11}
  1063:   10000100111 ~ {1,2,3,6,11}
  1069:   10000101101 ~ {1,3,4,6,11}
  1109:   10001010101 ~ {1,3,5,7,11}
  1123:   10001100011 ~ {1,2,6,7,11}
  1129:   10001101001 ~ {1,4,6,7,11}
  1163:   10010001011 ~ {1,2,4,8,11}

Mathematica

Select[Range[1000], DigitCount[Prime[#], 2, 1]-DigitCount[Prime[#], 2, 0]==-1&]

Crossrefs

Restriction of A031444 (positions of '-1's in A145037) to A000040.

Taking primes gives A095072.

Positions of negative ones in A372516, absolute value A177718.

The negative version is A372538, taking primes A095073.

A000120 counts ones in binary expansion (binary weight), zeros A080791.

A030190 gives binary expansion, reversed A030308.

A035103 counts zeros in binary expansion of primes, firsts A372474.

A048793 lists binary indices, reverse A272020, sum A029931.

A070939 gives the length of an integer's binary expansion.

A101211 lists run-lengths in binary expansion, row-lengths A069010.

A372471 lists binary indices of primes.

Cf. A003714, A031448, A035100, A037861, A053738, A061712, A066195, A104080, A211997, A372429, A372517, A372686.

Sequence in context: A281915 A102167 A214525 * A109637 A039513 A125265

Adjacent sequences: A372536 A372537 A372538 * A372540 A372541 A372542

Keyword

nonn,base

Author

Gus Wiseman, May 14 2024

Status

approved