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 1-4 of 4 results.

A095063 Number of fibodious primes (A095083) in range [2^n,2^(n+1)].

Original entry on oeis.org

1, 1, 1, 3, 4, 7, 14, 22, 41, 70, 133, 261, 433, 800, 1468, 2883, 5445, 10033, 19388, 36902, 70168, 134005, 256771, 493088, 947153, 1822376, 3514806, 6780667, 13103439, 25351723, 49085715, 95166843, 184656849, 358622060, 697126872
Offset: 1

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Author

Antti Karttunen, Jun 01 2004

Keywords

Crossrefs

Formula

a(n) = A036378(n) - A095064(n).

Extensions

a(34)-a(35) from Amiram Eldar, Jun 13 2024

A095084 Fibevil primes, i.e., primes p whose Zeckendorf-expansion A014417(p) contains an even number of 1-fibits.

Original entry on oeis.org

7, 11, 23, 29, 37, 47, 53, 67, 83, 97, 101, 109, 127, 137, 139, 149, 157, 163, 193, 199, 223, 241, 263, 271, 277, 281, 283, 311, 317, 331, 337, 359, 373, 379, 389, 397, 409, 421, 439, 443, 461, 499, 503, 521, 547, 557, 563, 577, 593, 601, 607
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Crossrefs

Intersection of A000040 and A095096.

Programs

  • Mathematica
    Select[Flatten[Position[Mod[DigitCount[Select[Range[0, 6000], BitAnd[#, 2 #] == 0 &], 2, 1], 2], 0]] - 1, PrimeQ] (* Amiram Eldar, Feb 07 2023 *)

A095280 Lower Wythoff primes, i.e., primes in A000201.

Original entry on oeis.org

3, 11, 17, 19, 29, 37, 43, 53, 59, 61, 67, 71, 79, 97, 101, 103, 113, 127, 131, 137, 139, 163, 173, 179, 181, 197, 199, 211, 223, 229, 239, 241, 257, 263, 271, 281, 283, 307, 313, 317, 331, 347, 349, 359, 367, 373, 383, 389, 401, 409, 419, 433
Offset: 1

Views

Author

Antti Karttunen, Jun 04 2004

Keywords

Comments

Contains all primes p whose Zeckendorf-expansion A014417(p) ends with an even number of 0's.
For generalizations and conjectures, see A184774.

Crossrefs

Intersection of A000040 & A000201. Complement of A095281 in A000040. Cf. A095080, A095083, A095084, A095290, A184792, A184793, A184794, A184796.

Programs

  • Maple
    R:= NULL: count:= 0:
    for n from 1 while count < 100 do
      p:= floor(n*phi);
      if isprime(p) then R:= R,p; count:= count+1 fi
    od:
    R; # Robert Israel, Jan 17 2023
  • Mathematica
    (See A184792.)
  • Python
    from math import isqrt
    from itertools import count, islice
    from sympy import isprime
    def A095280_gen(): # generator of terms
        return filter(isprime,((n+isqrt(5*n**2)>>1) for n in count(1)))
    A095280_list = list(islice(A095280_gen(),30)) # Chai Wah Wu, Aug 16 2022

A095281 Upper Wythoff primes, i.e., primes in A001950.

Original entry on oeis.org

2, 5, 7, 13, 23, 31, 41, 47, 73, 83, 89, 107, 109, 149, 151, 157, 167, 191, 193, 227, 233, 251, 269, 277, 293, 311, 337, 353, 379, 397, 421, 431, 439, 463, 479, 523, 541, 547, 557, 599, 607, 617, 641, 659, 683, 691, 701, 709, 719, 727, 733, 743
Offset: 1

Views

Author

Antti Karttunen, Jun 04 2004

Keywords

Comments

Contains all primes p whose Zeckendorf-expansion A014417(p) ends with an odd number of 0's.

Crossrefs

Intersection of A000040 & A001950. Complement of A095280 in A000040. Cf. A095081, A095083, A095084, A095290.

Programs

  • Python
    from math import isqrt
    from itertools import count, islice
    from sympy import isprime
    def A095281_gen(): # generator of terms
        return filter(isprime,((n+isqrt(5*n**2)>>1)+n for n in count(1)))
    A095281_list = list(islice(A095281_gen(),30)) # Chai Wah Wu, Aug 16 2022
Showing 1-4 of 4 results.