cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 11 results. Next

A095056 Number of primes with three 1-bits (A081091) in range [2^n,2^(n+1)].

Original entry on oeis.org

0, 1, 2, 1, 2, 3, 3, 0, 4, 2, 3, 2, 2, 2, 4, 1, 3, 4, 5, 3, 2, 1, 5, 1, 0, 2, 5, 2, 2, 8, 6, 0, 5, 3, 4, 2, 3, 2, 2, 0, 3, 5, 0, 1, 5, 3, 7, 0, 1, 2, 5, 1, 5, 2, 6, 0, 6, 0, 2, 3, 2, 1, 2, 0, 2, 3, 5, 3, 6, 2, 2, 2, 5, 2, 7, 1, 3, 2, 3, 1, 6, 2, 4, 3, 3, 2, 6, 1, 1, 5, 7, 2, 4, 2, 5, 0, 3, 4, 3, 1, 2, 1, 3, 0, 5
Offset: 1

Views

Author

Antti Karttunen and Labos Elemer, Jun 01 2004

Keywords

Examples

			From _Michael De Vlieger_, Feb 27 2017: (Start)
a(1) = 0 because there are no primes with three 1s in binary expansion between 2^1 and 2^2.
a(2) = 1 since the only prime between 2^2 and 2^3 with three 1s in binary expansion is 7 = binary 111.
a(3) = 2 since between 2^3 and 2^4 we have 11 and 13 (binary 1011 and 1101, respectively) have three 1s.
(End)
		

Crossrefs

Programs

  • Mathematica
    Table[m = Count[Prime@ Range[PrimePi[2^n] + 1, PrimePi[2^(n + 1) - 1]], k_ /; DigitCount[k, 2, 1] == 3]; Print@ m; m, {n, 24}] (* Michael De Vlieger, Feb 27 2017 *)

Extensions

More terms from T. D. Noe, Oct 17 2007

A095058 Number of primes with a single 0-bit (A095078) in range ]2^n,2^(n+1)].

Original entry on oeis.org

0, 1, 2, 2, 3, 0, 4, 4, 3, 1, 5, 1, 4, 0, 3, 2, 8, 1, 11, 4, 5, 0, 7, 1, 2, 0, 1, 5, 4, 0, 7, 5, 1, 1, 9, 0, 6, 0, 7, 1, 6, 0, 4, 7, 2, 1, 10, 3, 3, 1, 2, 1, 6, 0, 4, 3, 0, 1, 8, 3, 3, 0, 3, 1, 8, 1, 2, 2, 3, 0, 9, 1, 5, 2, 5, 8, 3, 0, 10, 3, 0, 2, 4, 4, 6, 1
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Comments

For large n, the average value of a(n) is about 4. See A138290 for the n such that a(n)=0. - T. D. Noe, Mar 14 2008

Crossrefs

Cf. A095018.

Programs

  • PARI
    a(n) = sum(k=2^n+1, 2^(n+1), isprime(k) && (#select(x->x==0, binary(k))==1)); \\ Michel Marcus, Sep 11 2015

A095019 Number of zero-bit dominant primes (A095071) in range ]2^n,2^(n+1)].

Original entry on oeis.org

0, 0, 0, 1, 0, 3, 3, 11, 10, 40, 52, 130, 154, 482, 649, 1756, 2483, 6479, 9640, 24022, 34812, 89306, 136739, 335115, 510833, 1265350, 1982321, 4781514, 7508064, 18079040, 28833595, 68709969, 110272081, 262002130, 425542739, 1000343760, 1632745091, 3828253857, 6305334325, 14683465908
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Crossrefs

Extensions

a(34)-a(40) from Amiram Eldar, Jun 13 2024

A095020 Number of one-bit dominant primes (A095070) in range ]2^n,2^(n+1)].

Original entry on oeis.org

1, 2, 2, 4, 5, 10, 16, 32, 48, 97, 175, 334, 529, 1130, 1850, 3953, 6276, 13911, 23248, 49564, 81622, 178910, 300311, 650703, 1091809, 2380394, 4062176, 8780393, 15021634, 32618497, 56134342, 121625616, 209889612, 455265038, 791458830, 1711760073, 2982211935, 6457387921, 11302458576, 24430016732
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Crossrefs

Extensions

a(34)-a(40) from Amiram Eldar, Jun 13 2024

A095052 Number of primes with number of 0-bits equal to one plus number of 1-bits (A095072) in range ]2^2n,2^(2n+1)].

Original entry on oeis.org

0, 1, 3, 10, 25, 78, 283, 906, 3044, 10920, 37920, 135182, 487555, 1764216, 6415902, 23585285, 86789112, 320972293, 1192327462, 4441973622
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Examples

			In the range ]2^4,2^5] 17 (10001 in binary) is the only such prime thus a(2) = 1.
		

Crossrefs

Extensions

a(17)-a(20) from Amiram Eldar, Jun 13 2024

A095053 Number of primes with number of 1-bits equal to one plus number 0-bits (A095073) in range ]2^2n,2^(2n+1)].

Original entry on oeis.org

1, 1, 5, 11, 28, 105, 362, 1093, 3659, 13001, 45171, 159510, 563833, 2008295, 7333827, 26730538, 97256891, 358079458, 1324674524, 4902380577
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Examples

			In the range ]2^2,2^3] 5 (101 in binary) is the only such prime thus a(1) = 1.
Similarly, in the range ]2^4,2^5] 19 (10011 in binary) is also unique in that respect, thus a(2) = 1 as well.
		

Crossrefs

Extensions

a(17)-a(20) from Amiram Eldar, Jun 13 2024

A095057 Number of primes with four 1-bits (A095077) in range ]2^n,2^(n+1)].

Original entry on oeis.org

0, 0, 0, 2, 2, 5, 4, 10, 6, 13, 11, 9, 16, 16, 18, 25, 15, 19, 15, 37, 17, 37, 29, 29, 32, 40, 23, 49, 31, 51, 39, 37, 30, 52, 46, 40, 42, 62, 43, 57, 42, 68, 52, 78, 60, 89, 54, 63, 59, 92, 58, 79, 82, 99, 73, 87, 47, 99, 74, 72, 81, 106, 56, 102, 85, 117, 85, 97, 64, 132, 93
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Crossrefs

Extensions

More terms from T. D. Noe, Oct 17 2007

A095054 Number of primes with number of 0-bits <= number of 1-bits (A095074) in range ]2^n,2^(n+1)].

Original entry on oeis.org

1, 2, 2, 4, 7, 10, 20, 32, 65, 97, 203, 334, 718, 1130, 2381, 3953, 8266, 13911, 28995, 49564, 105524, 178910, 376969, 650703, 1383287, 2380394, 5044969, 8780393, 18699214, 32618497, 69349061, 121625616, 259051224, 455265038, 968649497, 1711760073, 3647018733, 6457387921, 13745846521, 24430016732
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Crossrefs

Formula

a(n) = A095020(n) + (if n is odd) A095018((n+1)/2).

Extensions

a(34)-a(40) from Amiram Eldar, Jun 13 2024

A095055 Number of primes with number of 1-bits <= number of 0-bits (A095075) in range ]2^n,2^(n+1)].

Original entry on oeis.org

0, 0, 0, 1, 2, 3, 7, 11, 27, 40, 80, 130, 343, 482, 1180, 1756, 4473, 6479, 15387, 24022, 58714, 89306, 213397, 335115, 802311, 1265350, 2965114, 4781514, 11185644, 18079040, 42048314, 68709969, 159433693, 262002130, 602733406, 1000343760, 2297551889, 3828253857, 8748722270, 14683465908
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Crossrefs

Formula

a(n) = A095019(n) + (if n is odd) A095018((n+1)/2).

Extensions

a(34)-a(40) from Amiram Eldar, Jun 13 2024

A095059 Number of primes with two 0-bits (A095079) in range ]2^n,2^(n+1)].

Original entry on oeis.org

0, 0, 0, 1, 2, 4, 0, 9, 5, 14, 4, 16, 9, 18, 0, 21, 21, 21, 7, 41, 22, 31, 5, 37, 20, 33, 14, 37, 45, 47, 0, 69, 31, 36, 34, 55, 34, 71, 10, 60, 50, 69, 22, 81, 52, 59, 5, 97, 71, 79, 42, 67, 86, 95, 13, 103, 61, 81, 47, 98, 50, 110, 0, 108, 87, 116, 36, 125, 98, 98, 29, 126, 90, 125, 46, 107, 100, 125, 8, 158, 81, 109, 65, 156, 94, 131, 27, 127, 144, 146, 38, 167, 129, 137, 6, 127, 112, 178, 76
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Crossrefs

Programs

  • Python
    from sympy import isprime
    from itertools import combinations, count, islice
    def a(n): # generator of terms
        if n < 2: return 0
        b, d = (1<Michael S. Branicky, Dec 27 2023

Extensions

Added terms a(34)-a(99) from the Wagstaff paper. - N. J. A. Sloane, Jun 19 2011
Showing 1-10 of 11 results. Next