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.

A222601 Conjectured number of Fibonacci numbers with exactly n 0-bits in their binary representation.

Original entry on oeis.org

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

Views

Author

T. D. Noe, Mar 08 2013

Keywords

Crossrefs

Cf. A004685 (Fibonacci numbers in binary), A214853 (one 0-bit), A222602.

Programs

  • Mathematica
    f = Fibonacci[Range[0,100]]; Table[Length[Select[f, Count[IntegerDigits[#, 2], 0] == n &]], {n, 0, 20}]

A222602 Irregular triangle of conjectured Fibonacci numbers with exactly n 0-bits in their binary representation.

Original entry on oeis.org

1, 1, 3, 0, 2, 5, 13, 55, 21, 987, 8, 89, 233, 377, 34, 1597, 28657, 6765, 144, 610, 17711, 196418, 514229, 2584, 4181, 10946, 121393, 317811, 3524578, 46368, 1346269, 1836311903, 75025, 5702887, 24157817, 102334155, 165580141, 832040, 14930352, 701408733
Offset: 0

Views

Author

T. D. Noe, Mar 08 2013

Keywords

Examples

			The irregular triangle begins
{1, 1, 3},
{0, 2, 5, 13, 55},
{21, 987},
{8, 89, 233, 377},
{34, 1597, 28657},
{6765},
{144, 610},
{17711, 196418, 514229},
{2584, 4181, 10946, 121393, 317811},
{3524578}, {46368, 1346269, 1836311903},
{75025, 5702887, 24157817, 102334155, 165580141},
{832040, 14930352, 701408733}
		

Crossrefs

Cf. A004685 (Fibonacci numbers in binary), A214853 (one 0-bit), A222601.

Programs

  • Mathematica
    f = Fibonacci[Range[0,1000]]; Table[Select[f, Count[IntegerDigits[#, 2], 0] == n &], {n, 0, 20}]

A222295 Conjectured number of Fibonacci numbers with exactly n bits set in their binary representation.

Original entry on oeis.org

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

Views

Author

T. D. Noe, Feb 22 2013

Keywords

Examples

			We set a(1) = 4 because Fib(1) = 1, Fib(2) = 1, Fib(3) = 2, and Fib(6) = 8.
		

Crossrefs

Cf. A004685 (Fibonacci numbers in binary), A221158 (two bits set), A222296.
Cf. A011373 (number of bits set in each Fibonacci number).

Programs

  • Mathematica
    f = Fibonacci[Range[0,500]]; Table[Length[Select[f, Total[IntegerDigits[#, 2]] == n &]], {n, 0, 87}]

A221158 Fibonacci numbers with two 1's in the binary representation.

Original entry on oeis.org

3, 5, 34, 144
Offset: 1

Views

Author

Alex Ratushnyak, Feb 20 2013

Keywords

Comments

Fibonacci numbers of the form 2^a + 2^b, a>b.
Elkies (2014) proved that there are no other terms.
This sequence is one row of A222296. - T. D. Noe, Mar 08 2013

Examples

			144 = 128 + 16 = 2^7 + 2^4, thus it is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    Select[Fibonacci[Range[1000]], DigitCount[#, 2, 1] == 2 &] (* Alonso del Arte, Feb 21 2013 *)
  • Python
    from sympy import fibonacci
    print([f for n in range(100) if (f := int(fibonacci(n))).bit_count() == 2]) # David Radcliffe, Jul 03 2025

Extensions

full, fini keywords added by Max Alekseyev, May 13 2014
Showing 1-4 of 4 results.